27 Health Symptoms You Should Never Ignore, According to Experts

There are plenty of pesky health symptoms you can sleep off or handle at home. Small cuts, mild headaches, and light cramps rarely warrant a trip to the doctor. But what happens when these common symptoms become severe or persistent? If your headache won’t let up or your stomach cramps just keep getting worse, how long should you wait before calling your doctor?

“Certain illnesses and injuries should be evaluated and treated within a narrow time frame—often the sooner, the better,” says Jennifer Maynard, M.D., family physician at the Mayo Clinic. Whether your symptoms are sudden and severe or innocent but persistent, they could signal that your body is dealing with something serious.

Here are 27 common health symptoms you should never ignore, according to doctors.

Facial drooping or slurred speech

If your face droops, your arms feel weak, or you’re struggling to speak, you may be having a stroke—and you need to get help now. The most common type of stroke, an ischemic stroke, is life-threatening. But a drug called tissue plasminogen activator (tPA) can prevent long-term damage within 3 hours—or even better, 60 minutes—of stroke symptoms. “Doctors talk about the ‘golden hour,’ because the outcome is best if you’re treated before that passes,” says Ruth M. Brocato, M.D., family medicine physician at Mercy Personal Physicians.

Severe vomiting or diarrhea

Vomiting and diarrhea are common signs of food poisoning and stomach bugs. But if your symptoms are so severe you’re struggling to keep water down, dangerous dehydration can set in quickly—in as little as a day—so you need to call your doctor, Dr. Maynard says. You should also call them if your symptoms don’t improve within four days. That may mean you have an infection, rather than a virus, and you need a prescription to fight it off.

Deep wounds

If you gash your finger while cooking or get nipped by a dog at the park, don’t assume you’ll be fine with some Neosporin and a bandage. Doctors will typically only stitch a wound within 12 to 19 hours of the injury, and the window is even smaller if you’re at risk of infection. That’s because bacteria multiply quickly, and physicians don’t want to trap an infection, says Dr. Brocato. If you do get stitches, contact your doctor right away if your skin gets red or swollen.

Painful, bruised, or swollen limbs

If an injury leaves you swollen, bruised, and sore, assume it could be a broken bone—and get help within two days. “If you wait too long, a bone can start to heal in the wrong position,” says Stuart Fischer, M.D., orthopedic surgeon at the Center for Ambulatory Surgery. Even if you’re not sure, he says it’s a good idea to get an evaluation and X-rays. And if you think you broke a bone and the break punctures your skin, head to the ER immediately.

Itchy rashes or painful blisters

If you get a painful, itchy rash on one side of your body, it may be shingles—caused by the same virus as chicken pox. Other signs of shingles include fever, headache, and fatigue. If you experience any of these symptoms, talk to your physician and get a prescription antiviral to take, ideally within 48 to 72 hours. “The goal of an antiviral is to tamp down the virus,” says Dr. Maynard. “Once it’s fully circulating, it’s harder to get control of.”

Unusual vaginal discharge

If you experience vaginal pain, burning, or unusual discharge, don’t ignore it, says Michael Krychman, M.D., board-certified OB/GYN and clinical sexual counselor. These could be signs of sexually transmitted infection (STI). Quick treatment is key: It’s ideal to start therapy within a few days to quell your symptoms, stop the spread, and prevent complications. Some untreated STIs can progress to pelvic inflammatory disease (PID), which can cause painful scarring and infertility, says Laura Bachmann, M.D., co-director of the STD/HIV Prevention Training Center.

Trouble getting pregnant

If you haven’t gotten pregnant after lots of carefully timed, unprotected sex, you may be dealing with infertility—or you may have nothing to worry about. Fertility experts recommend waiting six months (if you’re over 35) or 12 months (if you’re under 35) before seeing a specialist. That’s because 85% of couples naturally conceive within 12 months of actively trying, per UCLA Health. Plus, if you’ve recently been on birth control, it could take several months for your hormones to return to normal, Dr. Maynard says.

Unexplained weight loss

Sudden weight loss can be dangerous—and concerning. “Unexplained weight loss can be indicative of many things, including ovarian cancer or an endocrine or autoimmune issue,” says Kecia Gaither, M.D., OB/GYN and maternal fetal medicine physician. If you suspect ovarian cancer, it’s especially important to get checked out. “That is known as the silent killer in women because symptoms don’t usually present until the disease has progressed,” she explains.

Frequent heartburn

Periodic indigestion is usually nothing to worry about. But if you experience heartburn a lot, talk to your doctor. “This can be a sign of cardiovascular disease,” Dr. Gaither says. “Heart disease is the number-one killer in women, and symptoms usually do not present themselves the same way they do in men.” It’s completely possible to mistake a heart attack for heartburn, so be on the lookout for subtle symptoms, like shortness of breath, nausea and indigestion, and pain in your arms, back, or neck.

Skin changes

If you notice a once-round mole has changed shape, size, or color, get it checked by a dermatologist. “This may be indicative of malignant melanoma, an aggressive form of skin cancer,” Dr. Gaither says. When in doubt, remember the ABCDEs of skin cancer: asymmetry, border, color, diameter, and evolution of the mole. If one of these key features changes, talk to your doc.

Hair loss

Shedding some hair in the shower is normal. But if you notice big changes in your hair thickness or the amount of hair you’re losing, talk to your doctor. “Hair thinning can mean many things,” Dr. Gaither says. Hair loss has been linked to menopause, vitamin deficiencies, and a range of health conditions—including more serious endocrine and autoimmune conditions, like thyroid disease and lupus, she adds.

Vaginal bleeding

Bleeding is par for the course during your period. But if you’re bleeding between periods—or after you’ve gone through menopause—you need to talk to a doctor. While your spotting may be no big deal, post-menopausal bleeding, in particular, can signal uterine cancer, Dr. Gaither says. And early diagnosis and treatment are key.

Constant thirst

There’s nothing wrong with staying hydrated. But if you’re constantly reaching for your water bottle and your thirst seems hard to quench, it’s worth mentioning to a doctor. This constant thirst could be a sign of diabetes, Dr. Gaither says, especially if it’s accompanied by other symptoms, like fatigue, nausea, or mood swings.

Breast changes

If you notice anything abnormal about the way your breasts look or feel, book an appointment with your gynecologist. “A breast mass, change in the skin on the breast, or nipple discharge may indicate breast cancer,” Dr. Gaither says. Swelling, dimpling, pain, and irritation are other signs to look for, per the American Cancer Society.

Jaw, shoulder, or back pain

Occasional soreness in your jaw, shoulder, or back may be nothing to worry about. But if you frequently—or suddenly—experience pain in these areas, it may be a sign of heart disease, Dr. Gaither says. Remember, heart attacks don’t always look the same, and women and men tend to experience different symptoms. Keep an eye out for telltale signs, like chest pain and shortness of breath, but trust your instincts if something feels off.

Severe headaches

Minor headaches happen. But if your headache comes on suddenly or feels incredibly painful, don’t try to sleep it off. Headaches—especially severe, sudden, or chronic headaches—can signal a serious health condition, like a stroke, brain tumor, or aneurysm.

Black, tarry stools

Your poop can tell you a lot about what’s going on in your body. So if it doesn’t look normal, there may be a problem. If your stools are black and tarry, you should tell your physician, Dr. Gaither says. “While this may reflect eating too much iron … it may [also] indicate a bleed within the gastrointestinal system,” she explains. The latter requires immediate attention and treatment.

Shortness of breath

Any time you’re short of breath, you should call your doctor—or head to the hospital. If your shortness of breath is accompanied by symptoms like a cough, sore throat, or runny nose, the culprit may be a common cold or casual infection. But if it isn’t, it could signal something more serious, like a blood clot or a heart attack, per the Mayo Clinic.

Chronic fatigue

It’s one thing to feel tired at the end of a long day. But if you’re constantly exhausted, your body may be trying to tell you something. Since chronic fatigue can signal everything from a vitamin deficiency to a serious health condition, it’s worth bringing up with your doctor, Dr. Gaither says.

Frequent urination

If you’re frequently running to the bathroom to empty your bladder, there may be something going on. If you’re also experiencing stomach cramps, pain while peeing, or a burning sensation, a bladder infection or urinary tract infection (UTI) could be to blame. But frequent peeing can also be a sign of diabetes, especially if it’s paired with symptoms like fatigue and extreme thirst, Dr. Gaither says.

Mood changes

Whether you’re suddenly struggling to manage your mood or just feeling more anxious and upset than usual, it’s worth mentioning to your doctor. Mental well-being is important, and any noticeable change in your mood or feeling shouldn’t be taken lightly, Dr. Gaither says. Whether your symptoms are caused by a short-term stressor or an underlying condition, your doctor can help you find a way forward.

Appetite loss

If you’re not eating enough—because you’re getting full quickly, having trouble keeping food down, or not experiencing much of an appetite—you need to talk to a doctor. Appetite loss has been linked to a slew of health conditions, including cancer, HIV, and thyroid dysfunction, per the Mayo Clinic. It may also be a sign of an eating disorder or mental health condition, and it can be caused by certain medications.

Unexplained weight gain

If you notice you’re rapidly gaining weight without changing your diet, lifestyle, or exercise routine, mention it to your doctor. Belly fat can be a sign of heart or liver disease, Dr. Gaither says, because a buildup of fluids can cause your abdomen to expand.

Trouble seeing

A sudden, unexpected change in your vision may not be a sign you need new glasses. Instead, it could signal a more serious health condition. Trouble seeing—in one or both eyes—is a common symptom of stroke, per the American Stroke Association. It could also be a sign of diabetes, per the Centers for Disease Control and Prevention (CDC).

Ankle or leg swelling

If you’ve spent all day on your feet, you might expect your legs and ankles to look a little swollen. But if they’re persistently swollen, it may be a sign of edema—when fluid builds up in certain parts of the body. Edema isn’t always cause for concern, but it can be caused by underlying heart, liver, or kidney conditions, per the Cleveland Clinic. So it’s worth bringing up to your doctor.

Excessive sleeping

Getting some extra rest may sound like a blessing. But if you’re sleeping way more than usual—or struggling to wake up in the morning—mention it to your doctor, says Dr. Gaither. Exhaustion is associated with a range of health conditions, and it can also be a sign of depression, so it’s a good idea to get evaluated.

Confusion or brain fog

If you’re suddenly struggling to focus—or you don’t really feel like yourself—mention it to your physician. Feeling confused or disoriented may be nothing, but it can also be a sign of a serious infection or a mental health condition. Remember, you know your body best. If something feels off, bring it up.