23 Subtle Signs of Serious Health Issues
Don't ignore these often inconspicuous symptoms of major medical issues.

There are plenty of obvious signs of serious health issues that everyone knows—like numbness in your arm indicating a possible stroke, or chest pains prior to a heart attack. But while these examples might lead you to assume that all serious conditions comes with similar in-your-face symptoms, that's just not always the case. In fact, many health problems hide in plain sight via seemingly innocuous symptoms that we tend to write off as nothing more than inconvenient aspects of aging. To help you be safe as opposed to sorry, we've rounded up the subtle unexplained bodily changes that could indicate something bigger, and more serious, is at play.
1
Bad breath

Bad breath is certainly unpleasant, especially for the person you are speaking with when you have it, but it's often chalked up to little more than having too much garlic at dinner or an embarrassing, but relatively harmless, reminder that you need to be more vigilant about oral hygiene. However, Rhonda Kalasho, DDS, a double-board-certified dentist in Los Angeles, California, says that in some cases, chronic bad breath may indicate a more concerning health condition.
"Foul-smelling breath that doesn't go away even after you brush and floss could be caused by things like diabetes, liver disease, and kidney disease," Kalasho says. "Be sure to visit your dentist to rule out any serious causes."
2
A metallic taste in your mouth

Here's a scary statistic: 90 percent of adults with kidney disease don't know they have it, according to the Centers for Disease Control and Prevention (CDC). That's because "symptoms of kidney disease can be subtle and easy to ignore," says George Aronoff, MD, vice president of clinical affairs at DaVita Kidney Care.
So what should you look out for as far as subtle symptoms go? "Ammonia breath or an ammonia or metal taste in [the] mouth," according to Aronoff. He notes that waste build-up in the body can also cause changes in taste.
3
Swollen extremities

In addition to changes in your taste, swelling of the feet, ankles, hands, or face may also indicate a problem with your kidneys, Aronoff says. This is a result of your kidneys not functioning properly, allowing excess fluid to build up in your body tissue, he says.
4
Frequent urination

Constantly needing to use the bathroom is certainly an inconvenience, but it's not something everyone feels the need to address with their doctor. However, they should, seeing as frequent urination could be a sign of diabetes, the seventh leading cause of death in America, according to the American Diabetes Association.
If left untreated, diabetes can lead to multiple issues including problems with your body's nerves, kidneys, and blood vessels, as well as greater risk of infections.
5
Chronic headaches

According to the World Health Organization, nearly half of adults experience headaches in some capacity. And because they're so common, they often aren't viewed as being anything more serious than an unavoidable annoyance caused by things like stress and dehydration. According to a 2015 study published in the Caspian Journal of Internal Medicine, however, persistent headaches—especially when accompanied by vomiting, nausea, and changes to your vision—could be a warning sign that a stroke is imminent.
6
Neck pain

Aches and pains in your neck can be brought on by viruses like the flu, or the result of more innocuous causes like over exercising and sleeping on an unsupportive mattress, but when the pain is extreme and you have little to no range of motion, it could be a sign of meningitis. This infection of the membranes covering the brain and spinal cord can lead to neck pain that makes lowering your chin to your chest difficult or nearly impossible, according to healthcare resource Merck Manuals. If it is meningitis, lack of treatment could lead to permanent neurological damage or even death, so be sure to not push off the pain.
7
Hiccups

For women in particular, one of the subtle but serious symptoms of a stroke is having hiccups, says Stephen Sinatra, MD, a cardiologist in Manchester, Connecticut. While there's no need to panic about the occasional case of hiccups, if they are frequent and accompanied with other symptoms like facial pain, shortness of breath, nausea, and feelings of weakness, it's time to go to the doctor.
8
Double vision

Christopher Zoumalan, MD, a board-certified oculoplastic surgeon in Beverly Hills, California, warns that if you start seeing double or find one or both of your eyelids beginning to droop, these can sometimes be signs of a brain aneurysm. These symptoms should be addressed immediately, especially if they are unexpected and seemingly unprovoked.
9
Panic attacks

According to 2018 data from Mental Health America, 56 percent of Americans with a mental health condition don't receive proper treatment. This includes conditions like panic disorder and anxiety, both of which may cause panic attacks. Not only is this lack of treatment detrimental to one's mental health, it's a potential physical risk as well, since panic attacks are also warning signs of potential heart disease.
"Although chest pain and a tightening sensation are the common and obvious symptoms of coronary artery disease, there can be less obvious symptoms," says Carolyn Dean, MD, a heart health specialist and author of The Magnesium Miracle. She notes that among these less obvious symptoms are panic, anxiety, and stress, all of which can cause chest pain that you may not immediately register as the sign of a bigger, heart-related health issue.
10
Persistent coughing

Chronic obstructive pulmonary disease, or COPD, is a lung disease that can be difficult to detect early on. And many patients develop a cough—often accompanied by tightness in the chest and trouble breathing—before they are given a diagnosis, the COPD Foundation says. If you begin to experience unexplained coughing that doesn't go away, schedule an appointment with your doctor.
11
Feeling less physically coordinated

This symptom is frequently ignored by both doctors and patients, mainly because people vary greatly when it comes to their physical coordination. But Anthony Kouri, MD, an orthopedic surgeon at the University of Toledo Medical Center, cautions that if you notice any changes in the level of control you have over your body, this could be a sign of amyotrophic lateral sclerosis, or ALS—also known as Lou Gehrig's disease.
"ALS is a progressive nervous system disease that destroys motor neuron cells and leads to worsening disability and death," Kouri says. "Early symptoms may include tripping or bumping into things, clumsiness or hand weakness, difficulty holding small objects, and muscle cramps or twitching."
12
Redness of the skin

If you notice pain or tenderness around a red area, typically on your leg or arm, Kouri says it's worth visiting the doctor because this could be a sign of necrotizing fasciitis, a rare but deadly bacterial infection that attacks the skin, the fat beneath the skin, and the fascia overlying the muscle.
"It may develop from a small cut, a surgical site, a bruise, a boil, an injection site, or from a small injury from a normal daily occurrence," Kouri says. "There are several conditions that have the same signs and symptoms as necrotizing fasciitis in the early stages. This is a very difficult diagnosis to make, even for experienced clinicians."
13
Fatigue

No symptom hides in plain sight more effectively than fatigue. That's why you need to trust your instincts on what you know about your body. You should also make sure to not overlook the issue if you are consistently feeling exhausted despite getting eight hours of sleep or you're finding it difficult to function due to your lack of energy. This may mean your fatigue may be a sign of a serious health issue like cancer, diabetes, or heart disease.
14
Frank's sign

If you have Frank's sign, a diagonal crease on one of your earlobes, that doesn't necessary mean you have immediate cause for concern. However, it's worth mentioning to your doctor, as this particular crease "correlates with coronary artery disease, peripheral vascular disease, and cerebrovascular disease," says Edna Ma, MD, a board-certified anesthesiologist in Los Angeles, California.
15
Bloating

We all get bloated once in a while, whether it's due to a big meal or drinking too much of water. But if you experience bloating on a consistent basis without any unidentifiable cause, it could be a sign of colon, ovarian, stomach, and pancreatic cancers, according to Harvard Health.
16
Irregular bowel movements

Common digestive woes like diarrhea and constipation are issues everyone deals with now and then, but they can also be a sign of colon cancer—and that's one of the reasons why that particular form of the disease is so life-threatening. "It's one of the deadliest illnesses out there because its symptoms are so mild that when they diagnose it, it's often too late," explains Nikola Djordjevic, MD, founder of MedAlertHelp.org. If you begin having issues with your bowel movements or notice blood in your stools, make an appointment with your doctor to address the problem as early as possible.
17
Unexplained weight loss

You haven't changed your diet or exercise regimen, but your clothes feel loose and the number on the scale has dropped. Instead of being cause for celebration, it could be serious cause for concern, according The American Cancer Society, which says this type of mysterious weight loss is one of the first signs of cancer—particularly in the stomach, lungs, esophagus, and pancreas.
18
Night sweats

There are myriad reasons why your body perspires while you lay in bed asleep, the majority of which aren't cause for serious concern. However, excessive or increased night sweats are also symptoms of cancer, according to emergency medicine physician Jack Springer, MD. Specifically, The Dana-Farber Cancer Institute notes that they can be a sign of lymphoma and leukemia, both of which require immediate treatment.
19
Bruising or bleeding easily

Some people naturally bruise more easily than others, but if you notice bruises appearing more frequently or easily than they used to, it could also be a sign of leukemia.
According to the Cleveland Clinic, leukemia patients get bruises from very minor bumps, plus they may bleed from their gums and noses. In the early stages of the disease, there are often no obvious symptoms so it's important to immediately see a doctor if you notice more bruising or bleeding.
20
Facial puffiness

Puffiness in the face is fairly common, especially if you've recently consumed more salty foods and alcohol than usual. But if the swelling in your face doesn't pass quickly or if it's more pronounced than usual, it could be a sign of a tumor, according to 2017 research published in The National Journal of Maxillofacial Surgery. Because tumors can restrict your body's blood flow, this often leads to blood building up in your face, causing the skin to expand.
21
Difficulty swallowing

If you have a cold or strep throat, trouble swallowing is often par for the course. But if you're not sick, this issue could be a sign of esophageal cancer, according to The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Medicine. And if this is your only symptom, don't let it deter you from seeking medical attention; in the majority of cases, the more serious symptoms don't emerge until the cancer has reached an advanced stage.
22
New marks on your skin

According to Michelle Lee, MD, a plastic surgeon in Beverly Hills, California, new marks on your skin that may be dismissed as freckles or moles could actually be melanoma, a life-threatening form of skin cancer.
"Signs of melanoma are the ABCDE's: asymmetrical; border edge isn't smooth; color is uneven; diameter is larger than a pencil eraser; and it's evolving in size shape or texture," explains Lee. "When caught early, melanomas are curable—but when caught late, they are the No. 1 cause of death among skin cancers."
23
Frequent heartburn

If you experience persistent heartburn, it could be a symptom of a condition called Barrett's esophagus, which, according to The Dana-Farber Cancer Institute, increases your risk of developing esophageal cancer. That being the case, it's important to always address your heartburn—and its level of severity—whenever you see your doctor.