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40 Silent Signs of Illness in Your Body

Pay attention to your body. It's trying to save itself.
FACT CHECKED BY Christopher Roback

Sometimes serious illnesses don't scream—they whisper, making their presence known with vague, nonspecific symptoms that can easily be explained away. In some cases, they might not be noticeable at all. Others might surface suddenly and disappear. How will you recognize them for what they are: silent signs of illness? By reading this. Body Network researched some of the most common warning signals and asked doctors what you should do if you see them. Don't get paranoid; be informed.

Subtle Changes To Your Hair

Cropped shot of Asian man worry about his hair loss and baldness problem. Conceptual of hair problem on men's head.

The eyes may be the window to the soul, but your hair can provide insight into your gut—and what nutrients you are (and aren't) putting in it. "A deficiency in protein and/or essential fatty acids can make your hair look dull, thin and/or be pluckable," says Amanda A. Kostro Miller, RD, LDN, a registered dietitian on the advisory board for Smart Healthy Living. "Other possible nutrient deficiencies that show signs in your hair: calorie restriction, protein malnutrition, iron, zinc, selenium, vitamin C, copper or manganese."

Body Network Says: "Always consult your doctor about changes," says Kostro Miller. "You may have a nutrient deficiency, or you could even have a more serious medical illness."

Chronic Fatigue

Tired man in car. Sleepy drowsy driver, fatigue. Driving and sleeping in vehicle. Exhausted, bored or drunk person. Serious upset man with stress, despair, anxiety or melancholy. Problem in traffic.

We all get tired. But chronic, intractable fatigue can be a sign of several serious illnesses—including depression, cancer, Long COVID, and even heart disease. "The heart pumps blood to every organ in the body," says Joshua S. Yamamoto, MD, a Washington, D.C.-based physician and author of You Can Prevent A Stroke. "In the absence of good blood flow—particularly to the brain and muscles—the body feels fatigued."

Body Network Says: If you're experiencing extreme tiredness that won't go away with rest, talk to your doctor, who can help get to the bottom of the cause. Especially if you have previously had COVID.

Unexplained Weight Gain

Young woman touching her belly looking in mirror at home

Unexplained weight gain can be related to a condition called hypothyroidism, in which the thyroid gland isn't producing enough of the hormone that makes your metabolism go. "In addition to weight gain, you might have other nonspecific symptoms like fatigue or sensitivity to cold," says Dina Merhbi, a registered dietitian in Montreal, Quebec. 

Body Network Says: If you're experiencing any of those symptoms, ask your doctor for a TSH hormone blood test. Imbalances in thyroid hormone can be treated with medication.

Frequent Fungal Infections

Man scratching his athlete's foot.Close up.

Recurrent athlete's foot, jock itch and yeast infections can be a major annoyance. They can also be an early sign of chronic illness. According to the American Diabetes Association, those fungal infections are "sometimes the first sign that a person has diabetes." In people with the condition, a yeast called Candida albicans—which causes those common skin irritations—has an increased tendency to overgrow. 

Body Network Says: The American Diabetes Association recommends that adults be tested for diabetes once a year. Diabetes can be treated with medication and lifestyle changes; untreated diabetes can lead to heart disease, vision problems and circulation issues that can lead to amputation.

RELATED: #1 Reason Your Body Needs Healthy Fats, According to Nutritionist

Facial Drooping

Blured photo of a woman suffering from vertigo or dizziness or other health problem of brain or inner ear.

"A new facial droop, with other signs such as arm weakness and/or speech difficulty, should be evaluated immediately by a doctor, as it can indicate a stroke," says Christopher Zoumalan, MD, FACS, a board-certified ophthalmologist in Beverly Hills, California. 

Double Vision

Young woman rubs her eyes after using glasses. Eye pain or fatigue concept.

"Another less common condition is sudden onset of double vision and a droopy eyelid," says Zoumalan. "This can sometimes be the cause of a brain aneurysm, and immediate evaluation by a doctor is vital." 

Subtle Changes to Your Fingernails

Hands of a woman playing with nails in stress

If you notice changes in your nails like ridges, spooning nails, white lines or excessive brittleness, you may have deficiencies in iron, folate, vitamin A, protein or zinc," says Kostro Miller. 

Body Network Says: See your doctor to rule out larger health problems, then "Talk to a registered dietitian to determine which nutrient deficiency is to blame," says Kostro Miller.

Unintentional Weight Loss


"This can feel like a blessing if you're overweight, but it may be a sign that your body is not properly absorbing nutrients," says Nancy Woodbury, RD, LDN, a registered dietitian nutritionist in Boca Raton, Florida. That could have a few explanations. It could be a sign of Type 1 diabetes, in which the body stops producing insulin. "The lack of insulin causes weight loss and high blood glucose levels because the body's cells become starved for energy," she explains.

Unintentional weight loss can also be a sign of several cancers. "Weight loss can also be a sign of cancer, because cancer cells cause a derangement in metabolism that rapidly consumes energy in a way that is very different than the weight loss caused by low-calorie dieting," says Woodbury. "One clue is that consuming more calories from food is often not effective by itself to reverse cancer-related weight loss." 

Body Network Says: Unexplained weight loss of 10 pounds or more can be a sign of cancer. It happens most often with cancers of the pancreas, stomach, esophagus, or lung, the American Cancer Society says. See your doctor if you're dropping weight without trying.


Close-up of Female Broken Arm in Plaster Cast. Caucasian Injured Woman in White T-Shirt Sitting and Holding Wrist in Gypsum Bandage with Physical Pain in Fractured Bone. Health Care concept

"Clumsiness is a symptom that is often ignored by patients and doctors alike," says Anthony Kouri, MD, an orthopedic surgeon with the University of Toledo Medical Center. "Because many of these symptoms are also things that occur as we age, it is passed off as simple aging by most people. Though some people may be naturally clumsy, this can also be a sign of something much worse." 

Body Network Says: Clumsiness can be a sign of progressive nervous system disorders including Parkinson's Disease, multiple sclerosis and ALS. "Early symptoms may include tripping or bumping into things, clumsiness or hand weakness, difficulty holding small objects, and muscle cramps or twitching," says Kouri. If that's happening to you, schedule an appointment with your doctor.

RELATED: 7 Ways to Lose 25+ Pounds Without Taking Weight Loss Drugs, Says Expert


Shot of illness young woman coughing in the street.

A cough is likely just a cold or allergy. But a recurrent cough should be investigated by a doctor. It's one of the symptoms of mesothelioma, a so-called "silent" cancer that takes decades to develop and is often diagnosed among the older demographic. "With asbestos exposure being this cancer's only known cause, it historically has affected blue collar workers and military personnel," says Colin Ruggiero, a health advocate for "Those who were susceptible to asbestos exposure should be mindful of the subtle symptoms that this disease presents, like chest pain, fatigue, muscle weakness and coughing. Commonly, mesothelioma will be misdiagnosed with the flu, pneumonia, and other less severe illnesses." 

Body Network Says: If you do—or did—a job that's prone to asbestos exposure, tell your doctor, monitor any symptoms and keep regular doctor's appointments.

High Blood Pressure

A doctor is taking the blood pressure of a woman who is wearing sportswear.

According to the American Heart Association, high blood pressure (a.k.a. hypertension) is often referred to as "the silent killer" because it often has no symptoms until it's done significant damage to your heart and arteries.

Body Network Says: If your blood pressure is normal (less than 120/80), the AHA recommends getting it checked at your yearly physical. If your blood pressure is high, your doctor may recommend checking it more often (including at home) and may prescribe lifestyle changes and medication.

Bleeding After Brushing


If your gums have begun to bleed when you brush your teeth, talk to your dentist. "That bleeding you may see in the sink after flossing or brushing is no little issue," says Dr. Rhonda Kalasho, a dentist in Los Angeles. "Just imagine you were cleaning your knees and suddenly they started to bleed, you would probably be rushing to the emergency room."

The bleeding could be a sign of periodontal disease, the destruction of bone and tissue caused by a proliferation of bad bacteria below the gums and on teeth. "Periodontal disease is the number one reason for tooth loss," says Kalasho. "It has been linked to cardiovascular disease and Alzheimer's disease. This bad bacteria can travel into the bloodstream, causing septicemia or infections on organs." 

Body Network Says: "Make sure to brush, floss, and see your dentist at least 2-3 times a year for the best oral upkeep, not only for the sake of your teeth, but for your entire body," says Kalasho.

Bad Breath

A man checks for bad breath and breathes with his hands. he has bad breath Concept of oral and dental health

"Bad breath could be something benign, like having a little tooth much garlic in your dinner the night before, or could be linked to something more serious," says Kalasho. "Foul-smelling breath that doesn't go away even after you brush and floss could be caused by diabetes, liver disease, kidney disease, tonsillar stones, GERD or bronchitis."

Body Network Says: "Be sure to visit your dentist to rule out any serious cause for your bad breath," says Kalasho.  

Eye Problems

Close up portrait of an attractive man with eyeglasses. Poor young guy has eyesight problems. He is rubbing his nose and eyes because of weariness

Most of us are on guard for the vision disorders that accompany aging, like cataracts and glaucoma. But eye problems can also signal diabetes. According to the American Diabetes Association, people with diabetes are 60 percent more likely to develop cataracts and 40 percent more likely to suffer from glaucoma. 

Body Network Says: Get tested for diabetes regularly, particularly if you're dealing with either of those eye issues.


Stressed woman scratching itchy arm after insect bite in a field of peach trees in spring time

Itchy skin can have a number of relatively innocuous causes, from allergies to dry air to a dusty bedroom. But protracted skin itching can be a sign of kidney disease. "Itchy skin can be a sign of the mineral and bone disease that often accompanies advanced kidney disease, when the kidneys are no longer able to keep the right balance of minerals and nutrients in your blood," says the National Kidney Foundation.

Body Network Says: If you have persistent skin itching, talk to your physician, who can order simple tests to rule out kidney problems.


Passed out man drooling in bed

Snoring could be a sign you have sleep apnea, a condition that's linked to a variety of serious illnesses, including cardiovascular disease. During sleep apnea, you stop breathing—for up to a minute—until the brain wakes you up to start breathing again. According to Harvard Medical School, sleep apnea is present in up to 83 percent of people with heart disease, and untreated sleep apnea could raise your risk of dying of heart problems by up to five times. 

Body Network Says: If you've been told you snore, talk to your doctor about it.

Changes in Handwriting


Handwriting that gets shakier or progressively smaller could be a sign of a nervous-system disorder such as Parkinson's Disease. According to the National Parkinson's Foundation, sometimes when people with the disease write in longhand, each sentence becomes smaller or words are more crowded together. Studies show that 97 percent of people whose handwriting changes this way are in an early stage of Parkinson's.

Body Network Says: If you notice that your handwriting is changing, consult your health care provider.


Angry screaming sad upset girl in outdoors street coffee shop wooden cafe sitting with modern laptop pc computer, disturb problem during free time. Mobile Office. Lifestyle freelance business concept

If you're increasingly cranky about the literal or figurative kids on your lawn, you could be turning into a charming old curmudgeon—or you might be exhibiting signs of depression. Irritability is an lesser-known (but very common) symptom of the mood disorder, which is also characterized by chronic feelings of sadness, hopelessness or a loss of enjoyment in previously pleasurable activities.

Body Network Says: Talk with your doctor. Many treatment options are available.

Swollen Gums

Sad frowning handsome brunette young man with beard touching cheek and looking into mirror in bathroom while getting bad tooth during cleaning teeth

Gum disease, in which the gums are swollen or inflamed, could be a sign of heart disease, according to a study of more than 11,750 adults published in the journal Hypertension. Researchers found that half the people who reported being treated for high blood pressure also reported having gum disease. The connection isn't clear, but scientists think inflammation in the gums might trigger or worsen inflammation in other areas of the body, including arteries.

Body Network Says: Take good care of your teeth and gums, including twice-annual visits to the dentist for a checkup and cleaning.

Swollen Feet Or Ankles

Swollen feets because water retention in the body

Swelling in your feet or ankles could indicate that you spent too many hours on your feet or that you overdid it at the gym. According to the National Kidney Foundation, kidney disease can cause fluid to build up in the body; swollen extremities could mean you're retaining sodium, which the kidneys aren't able to adequately clear from the blood. 

Body Network Says: Swollen lower extremities could be a sign of several issues, some more serious than others, ranging from heart disease to varicose veins. If you're experiencing it on a consistent basis, see your health care provider to get it checked out.

Erectile Dysfunction

We have a problem. Upset young man sitting on the edge of the bed and holding his head against the background of a girlfriend, lying in bed.

If you're having difficulty getting or keeping an erection, your worries might not be confined to the bedroom. According to the Mayo Clinic, erectile dysfunction is often an early sign of heart disease. If your heart isn't pumping as it should, the arteries carrying blood to your penis might not be getting enough. (And therefore neither are you.)

Body Network Says: If you're experiencing ED, file your ego away and talk to your doctor ASAP. 

Profuse Sweating

Shot of an unrecognizable man undressing because of the heat and sweat on a hot summer day

In a study published in the journal Circulation, scientists analyzed data on more than 2,000 heart attack patients and found a surprising commonality. Nearly 54 percent of them had experienced profuse sweating as a symptom of their heart attack.

Body Network Says: Be aware of the common (and not-so-common) symptoms of a heart attack.

Dry Eyes

Tired young man feel pain eyestrain holding glasses rubbing dry irritated eyes fatigued from computer work, stressed man suffer from headache bad vision sight problem sit at home table using laptop

According to a study published in the American Journal of Ophthalmology, nearly 50 percent of patients with untreated hepatitis C reported lower tear production, a.k.a. dry eye. "Dry eye syndrome is the most frequently observed ocular feature in HCV [hepatitis C] infection," wrote the study authors.

Body Network Says: Having dry eyes doesn't mean you have hepatitis C. But the condition can affect your productivity and quality of life, so consult your physician. Several treatments are available. And if you have risk factors for Hep C, get tested. New medications have made the condition increasingly curable; untreated, it can lead to liver failure.


Sick woman with headache sitting under the blanket

Frequent or severe headaches are two lesser-known signs of high blood pressure. They happen because high blood pressure strains blood vessels in the brain, causing them to leak blood, which leads to swelling and pain. 

Body Network Says: The American Heart Association recommends that you have your blood pressure checked once a year. 

A Broken Bone

Closeup of asian man's arm with long arm plaster, fiberglass cast therapy cover by blue elastic bandage after sport accident. Appropriate treatment in western medicine.

"Perhaps one of the most under-screened and under treated conditions is osteoporosis," says  Adam Kreitenberg, MD, a rheumatologist in Tarzana, California. "Osteoporosis is a 'silent' condition characterized by the progressive loss of bone mineral density increasing one's risk for bone fractures. There are no signs or symptoms of osteoporosis until a fracture occurs. The most commonly fractured bones are the spine, hips and wrists. Those at increased risk include post-menopausal women, and those people with poor nutrition, low body weight, frequent falls and those taking certain medications, like steroids and anti-seizure medications."

Body Network Says: "All women over 65 and men over 70 years of age should be screened for decreased bone density and their risk for fractures," says Kreitenberg. "Once diagnosed, osteoporosis may be treated with a number of different medications to decrease further bone loss and decrease the risk for bone fractures." 


An attack of asthma, allergies at home. An elderly woman is sitting on the sofa, holding her chest and coughing, feeling severe pain, suffocating.

"Frequent 'deep sighing' can be a sign of poorly controlled asthma," says Brian Greenberg, MD,  an allergist-immunologist in Los Angeles.

Body Network Says: We're all sighing more than usual these days. But if you notice that you're experiencing any breathing issues, see your healthcare provider.

More Frequent Urination

public toilet sign board with white woman and man figure and arrow on blue background or surface with noise effects. public toilet or wc sign board photo with selective focus and copy space on blue

If you need to urinate more frequently, it could be a sign of diabetes. According to the Mayo Clinic, that happens when excessive glucose (sugar) builds up in your blood, and your kidneys spur more urination in an attempt to clear it.

Body Network Says: If you notice any change in your bathroom habits, call your doctor.

Changes In Urination

Adult man in a toilet at home

If you're seeing a difference in your urine, such as foaminess, it could signify kidney disease. "Chronic Kidney Disease (CKD), which affects 31 million American adults, is sometimes known as a silent condition because it doesn't always make people feel sick in its early stages," says Jennifer Parker, RD, LDN, lead dietitian with Fresenius Medical Care in Gainesville, Florida. "Unfortunately, symptoms may not appear until the kidneys have stopped working well enough to filter blood on their own." Other signs of kidney disease include fatigue; itching; swelling in your hands, face or legs; shortness of breath; or pain in the small of your back.

Body Network Says: "Kidney function tests that can help detect CKD early at annual check-ups are simple and inexpensive," says Parker. "The National Kidney Foundation offers free kidney health screenings where you can get a better idea if you're at risk or might already have some level of kidney disease." 

Lifestyle changes that benefit the kidneys include quitting smoking, controlling blood pressure and blood sugar and eating a plant-heavy diet. "Decreasing your intake of processed foods, which are high in sodium and added sugars, and focusing on eliminating red meat can help," says Parker. "Start choosing fresh fruits, veggies, whole grains and beans today. Your kidneys, and your heart, will thank you."


Unhappy young woman standing in front of a mirror and holding hands on her bloating stomach.

Feeling gassy after eating—or prematurely full at meals—can be a sign that you ate too fast or gulped that grapefruit LaCroix. But persistent bloating can also be a symptom of ovarian cancer, the American Cancer Society says. Ovarian cancer is one of the hardest cancers to detect, because its symptoms (like bloating) can be vague. 

Body Network Says: If you're consistently feeling bloated or experiencing digestive issues, discuss it with your doctor.

Burning in Your Chest or Throat

Terrible pain in his throat. Frustrated handsome young man touching his neck and holding a glass of water while sitting on the couch at home

Heartburn is usually a sign of acid reflux. But according to Harvard Medical School, it could also signify a "silent" heart attack, a.k.a. silent myocardial infarction (SMI). These milder heart attacks have less intense symptoms, with fatigue, physical discomfort, cold sweating, or mild discomfort in the center of the chest. Silent heart attacks account for 45 percent of all heart attacks and affect men more than women. But women are more likely to have non-traditional symptoms of a major heart attack, including nausea, indigestion, stomach pain or chest pressure that spreads to the throat. 

Body Network Says:  If you're experiencing unusual pain or discomfort in any part of your body, get it checked out. 

Shortness of Breath


According to Splaver, signs of congestive heart failure can often mimic asthma. Shortness of breath, wheezing or coughing could be a sign your body is retaining fluid, which can occur when the heart isn't able to maintain proper circulation. 

Body Network Says: If you're having chronic shortness of breath, see your doctor and describe your symptoms fully.

Night Sweats

Depressed senior man lying in bed cannot sleep from insomnia

Waking up sweaty might be a sign of global warming, menopause or that you need to change your AC filter. But night sweats can also be an early sign of cancer, including lymphoma or leukemia. 

Body Network Says: If you're having night sweats, see your doctor for a CBC (complete blood count) blood test, which includes a white blood cell (WBC) count. A high WBC could be a sign of cancer and warrants further investigation.

Feelings of Weakness

Blonde young woman give up workout in gym, fail.

Like a heart attack, a stroke can be "silent." In fact, "silent" strokes affect 8 to 10 million people each year—so many the American Stroke Association issued new guidance about them in 2016. "It's important to go to your family physician if there are concerns about neurological symptoms like weakness or speech difficulty," said Eric E. Smith, MD, an associate professor of neurology at the University of Calgary. "Silent strokes put people at risk not only for future symptomatic strokes but also for cognitive decline and dementia."

Body Network Says: See your physician if you have those symptoms—a "silent" stroke can be treated to prevent a full-blown stroke.

Easy Bruising

Woman sitting on a sofa examines a bruise on her leg.

Bruising more easily than usual, or having unusually large bruises, can be a sign of leukemia, according to the Leukemia & Lymphoma Society. They occur because leukemia destroys platelets, the cells in the blood that cause it to clot.

Wounds That Won't Heal

Modern rehabilitation physiotherapy

Sluggish wound healing, or wounds that won't heal at all, is often seen as an unfortunate condition that accompanies aging. The real culprit is poor circulation, which can be a sign of diabetes. 

Body Network Says: According to the Cleveland Clinic, if you have a sore that doesn't heal within three months, it qualifies as a chronic wound, and you should see a doctor about it as soon as possible. Untreated chronic wounds can result in infection, neuropathy and even amputation.

Sudden Vision Changes

Poor Eyesight. Senior Man Squinting Eyes Reading Message On Phone Wearing Eyeglasses Having Problems With Vision Sitting On Couch At Home. Ophtalmic Issue, Bad Sight In Older Age Concept

A sudden change in your vision—such as blurriness, fogginess or loss—can be disconcerting. It could also be the sign of a serious issue. According to the University of Virginia Health System, the explanation could be minor, such as migraine headache or, more rarely, a ministroke or transient ischemic attack (TIA).

Body Network Says: Any sudden change in vision should be reported to your doctor ASAP.

Excessive Thirst

Happy beautiful young woman drinking water. Smiling caucasian female model holding transparent glass in her hand. Closeup. Focus on the arm

If you're constantly feeling excessively thirsty, it could be a sign of diabetes. The condition is caused by high levels of sugar in the blood; the body reacts by requesting more and more water in an attempt to clear it. 

Body Network Says: If you're experiencing excessive thirst, see your doctor, who may test you for diabetes. 

Hearing Loss

Close up of young brunette female holding painful ear, suddenly feeling strong ache. Unhealthy caucasian woman 20s suffering from painful otitis sitting on couch at home. Health problems concept

Hearing loss can sneak up gradually, and it's easy to explain away as a natural consequence of aging or people around you mumbling. But if you're not hearing as well as you used to, you don't have to live with it. 

Body Network Says: Make an appointment with your primary-care doctor or a board-certified audiologist, who can evaluate your hearing and recommend hearing aids if you need them. 

Scaly Patches on the Skin

Man With Itchy Skin. Allergy Or Psoriasis

Some people mistake them for age spots, but they could be a sign of diabetes. Painless light brown, scaly patches (often oval or circular) appearing on the body, most frequently on the front of the legs, could signify a condition called diabetic dermopathy. Why? According to the National Diabetes Foundation, diabetes can cause changes in the body's small blood vessels.

Body Network Says: The American Diabetes Assocation recommends that adults be tested for diabetes once a year. If you notice scaly patches on your skin, see your primary-care physician or a dermatologist, who can help pinpoint the cause.

Jaw Pain

Close up man mouth with dry lips and unhappy face, Closeup shot of bearded half men face with chin on his hand with sad face.

Heart attacks can have unusual symptoms, including headaches, nausea – even pain in the jaw. According to a 2012 study published in the Spanish-language journal Medicina Oral Patologia Oral Y Cirugia Bucal, researchers found that about one in every 10 heart attacks begins as jaw pain.

Body Network Says: Pay attention to any unusual symptoms or pains that won't go away. Anything that just doesn't feel right should be checked out by a doctor.

Michael Martin
Michael Martin is a seasoned writer and editor with a passion for helping people make life-improving decisions. Read more