The most dangerous diseases are the ones that sneak up on you. Left untreated, conditions like diabetes, heart disease, cancers, and other illnesses wreak havoc on the body. By the time you realize that you are sick, there may have already been significant progression or damage.

With the ongoing coronavirus pandemic, it’s more challenging than ever to manage your healthcare. Many people brush off the symptoms they are experiencing. This is especially true for those who don’t have health insurance or who are especially busy and don’t necessarily want to take time off work to go to the doctor. Below, we’ll take a look at some of the symptoms of the sneakiest diseases and how to tell if you have them. Now more than ever, it’s important to be aware of potential problems and take control over your health.

1. You Have Swelling Feet and Ankles

Swelling of the feet and ankles is called edema. Edema is common, particularly if you’ve been standing or walking a lot. It’s also common after a flight or during pregnancy. In some cases, however, this swelling may be the result of an underlying condition that could be serious, or even fatal.

Usually, leg swelling happens from gravity’s effect of pulling blood downward when you spend a lot of time on your feet. As blood is pulled downward, some of the water might seep into the tissues, which causes edema. When swelling happens frequently or even without being on your feet for long periods of time, it might be the result of an underlying health condition. Some conditions that cause edema include: Phlebitis, Venous Insufficiency, kidney disease, liver disease, Deep-Vein Thrombosis (DVT), and heart failure.

2. High Levels of Stress Cause Physical, Emotional, and Behavioral Symptoms

At a regular level, stress helps people adapt to everything going on around them. It keeps you motivated, alert, and ready for anything the day throws at you. When stress is constant, however, it can be a silent killer. Stress takes a serious toll on the body and affects the digestive, nervous, and gastrointestinal systems. Not only is it physically exhausting, but stress also affects mental health. Physically, stress causes problems like high blood pressure, difficulty sleeping or exhaustion, headaches, jaw clenching and muscle tension, stomach or digestive problems, aches and pains, chest pain, dizziness, shaking, a weakened immune system, and difficulty having sex. It also leads to mental health problems like depression, anxiety, irritability, and panic attacks.

Furthermore, people with stress may have behavioral problems. This includes eating too much or too little, using tobacco, drugs, or alcohol, social withdrawal, angry outbursts, and more. One of the struggles of identifying stress is that some people function really well in a high-stress environment, until they don’t. If you are having symptoms like the ones mentioned above, it may be best to talk to your doctor and consider what changes you can make to reduce the amount of stress in your life.

3. Bad Breath Could Indicate Heart Disease

A little bad breath is normal, especially if you’ve just finished a meal of onions, garlic, sardines, or another strong-smelling food. When bad breath is a regular occurrence, however, it could be a sign of gingivitis or gum disease. These might not seem like serious diseases on their own, but they have been linked to inflammation in the heart and might even contribute to heart disease.

When you do not brush and floss your teeth regularly, the bacteria feeds off the food left behind on your teeth and gums. As it multiplies, some bacteria may pass into the bloodstream. This produces a small inflammatory response in most cases, as the body fights off the bacteria. When the inflammation is persistent, it can damage the arteries around the heart and eventually lead to heart disease.

4. Fatigue is a Symptom of Several Conditions

Fatigue is a symptom that is often overlooked because people just assume they are tired. Tiredness, however, is something that can be relieved with rest and sleep. Fatigue is a step beyond just being tired and feels overwhelming. It also cannot be relieved with rest and sleep.

With fatigue, it’s very important to watch for other symptoms that could help your doctor diagnose you. Losing weight or mysterious lumps and bumps might indicate cancer, while fatigue and easy bruising could be caused by anemia. Some other diseases known for causing fatigue include diabetes, sleep apnea, depression, celiac disease, and restless leg syndrome. Often, there is blood work and other diagnostic tests that your doctor will run first to help with a diagnosis.

5. Night Sweats Also Have Many Causes

Night sweating is more than just being a little too hot at night. People who experience night sweats may wake up covered in sweat regardless of the temperature in the room. It disrupts sleep patterns and may even be an indication of an underlying health problem. Night sweating is normal when it happens as a result of menopause, which happens to most women sometime around their 50s as hormone levels begin to drop.

It’s also a side effect of some types of medication, including hormone-blocking drugs used to treat cancer, antidepressants, and diabetes medication. However, according to the Mayo Clinic, night sweating also is a common symptom of a number of diseases. It could indicate a problem with the thyroid, anxiety disorders, certain cancers and leukemia, bone infection, bacterial infection, or other problems.

6. Sudden, Unexpected Weight Loss Indicates Severe Problem

It’s all too easy to get excited about shedding a few unwanted pounds. When weight loss is unintentional or significant, however, it can indicate an underlying problem ranging from anxiety or excess stress to celiac disease, worsening COPD, or even cancers. Unintentional weight loss is any weight loss that happens without diet and exercise, especially when it happens rapidly.

Even in a healthy person, losing too much weight at once is dangerous. Fast weight loss puts too much strain on the body. Your body may think that it’s starving, so your metabolism will slow down. It also causes the loss of muscles, rather than fat, and makes it harder for your body to absorb the nutrients it needs. In turn, this may lead to additional health problems. Always make sure to speak to your healthcare provider if you experience sudden or extreme weight loss.

7. Chronic Neck or Back Pain May Be Caused by Poor Posture

Many people perform repetitive movements or sit in the same posture a lot of time at work. Maintaining proper posture through the day strains ligaments in the neck. In fact, for every inch that your head shifts forward at an angle, there are ten more pounds of pressure on the muscles found in your upper back and neck. This can result in long-term injury for some people, especially in a world where we spend so much time looking down at our phones.

In addition to symptoms like knots and having pain, chronic neck or back pain leads to further problems like spinal dysfunction and disk degeneration. Even though it may feel unnatural, adjusting your posture properly may help the problem. If pain persists, then physical therapy may be beneficial. A physical therapist will show you exercises that you can use to build up the muscles around the spine and neck, providing it with proper support.

8. Snoring May Be Serious, Not Just Annoying

The sounds from someone snoring are caused by something blocking air as it travels through their airways. As the air is forced through tight or blocked areas, the tissues in the throat and nasal passage vibrate. This creates the sound that you hear from snoring. While snoring may happen from being overweight, loss of muscle as you age, or drinking alcohol, it may also be caused by sleep apnea. When snoring happens long-term, it increases the risk of stroke, heart attack, and other health problems. It may also be indicative of sleep apnea, a condition where breathing may stop altogether.

As the body works over time to keep breathing during sleep, the extra strain on the chest and diaphragm leads to other conditions. Left untreated, sleep apnea may cause irregularities in heart rhythm and stop oxygen from getting to the organs. It can also cause high blood pressure, cardiomyopathy, and even diabetes. Constant snoring also stops you from getting enough sleep. Sleeping enough is critical to maintaining energy levels and focus through the day. Getting enough sleep also gives the body enough time to reboot and heal itself, so it’s important for staying healthy as well.

9. Frequent Nighttime Urination May Also Be Sleep Apnea

Another symptom of sleep apnea is notcturia, or frequent nighttime bathroom trips. In one study, research showed that 84% of people diagnosed with sleep apnea frequently woke up to pee at night. This happens because the body is not getting the oxygen it needs. As carbon dioxide levels increase in the blood, it becomes more acidic. The acidity causes the muscles of the lungs to constrict and your heart rate to drop.

In response to these changes, the body starts to panic. Your heart races and sends out a signal that there is too much fluid in the body. In turn, you’ll wake up to use the bathroom. While this is a great defense mechanism for the body, it’s important to address sleep apnea because it can be fatal if left untreated. Your healthcare provider can run tests that will provide a diagnosis for you.

10. Frequent Nausea is a Sign of Parkinson’s Disease

Having an upset stomach is something people usually brush off. It might be associated with drinking too much coffee, having jitters, or eating something your stomach doesn’t agree with. When nausea happens frequently, however, it might be a sign of something more. If nausea is often accompanied by trouble swallowing and constipation, this could be a sign of Parkinson’s disease.

These two things are connected because Parkinson’s disease affects the nervous system and the way that the muscles interact with each other. When the muscles of the digestive tract aren’t working properly, it results in the inability to swallow and for other areas of your digestive system to struggle. Often, Parkinson’s symptoms, like trembling, that are associated with the disease happen later in its progression. By identifying it sooner when nausea symptoms happen, steps can be taken to slow progression and improve quality of life.

11. Depression Could Indicate Thyroid Problems

Sadness is something that everyone experiences as they go through the ups and downs of life. Some people even experience extreme sadness that makes it hard to carry out day-to-day tasks, usually after something significant happens. By contrast, depression symptoms are more severe than sadness. People with depression lose interest in things they once loved and have trouble with their day-to-day life. Episodes of depression could be brought on by an outside factor or they could happen sporadically. These periods last longer than two weeks.

While depression is a disease on its own, it can often have another underlying cause. Thyroid disease or vitamin D deficiency could also be causing depression. Your thyroid gland is located in your neck and it plays the important role of regulating your metabolism and controlling energy levels. When your thyroid isn’t producing enough hormones, it may result in depression. This connection is so strong, it’s considered typical practice to test the thyroid in people with depression.

12. Depression Also Indicates a Possible Vitamin D Deficiency

According to research from the CDC published in 2006, around 25% of the United States population is deficient in Vitamin D and another 8% are at risk for deficiency. Vitamin D plays a role in depression because it’s a pre-cursor for key hormones that help with emotional regulation. It also does things like providing essential minerals for healthy bones and teeth and helping with calcium absorption.

Handling vitamin D deficiency is important because it causes more than just depression. Research in past decades has linked low levels of Vitamin D in the body with autoimmune disorders, cardiovascular disease, obesity, osteoporosis, diabetes, and cancers. You can have Vitamin D levels tested with a simple blood test. If levels are low, getting more sunshine, eating dietary sources of Vitamin D, or taking a Vitamin D supplement may help resolve problems like depression.

13. Slow-Healing Cuts Could Be Vitamin D Deficiency

Slow-healing cuts and sores are most commonly associated with diabetes. With high levels of glucose in the blood, it doesn’t have as much room for the important nutrients and proteins needed for the body to heal itself. However, a lesser-known cause of slow-healing cuts is Vitamin D deficiency.

Research shows that Vitamin D plays a role in many bodily processes beyond keeping the teeth and bones healthy. A study published in the Journal of Dental Research took a look at the link between Vitamin D deficiency and healing following dental surgery, finding that low levels of Vitamin D resulted in a much longer healing process.

14. Indigestion May Be Underlying Heart Problems

Indigestion is something that describes pain or discomfort most commonly felt after eating. It usually affects the upper digestion area. Some common symptoms include heartburn, feeling bloated, nausea, and feeling full soon after eating. In some cases, indigestion is indicative of digestive issues like GERD (acid reflux), IBS, or ulcers. It may also be caused by gastroparesis, a condition where the digestive tract falls asleep that is most common in people with diabetes.

In other cases, indigestion might be a result of heart problems. Chest pain is something easily mistaken for heartburn, especially when it’s caused by a partial blockage of the vessels and not total blockage. Pain can also radiate outward, moving from the chest into the abdomen, neck, jaw, arms, or back. Often, this is brought on by episodes of stress but it does indicate a serious underlying problem. If the vessels leading to the heart are completely blocked, it may cause a heart attack.

15. Frequent Fungal Infections Indicate Diabetes

One of the lesser-known symptoms of untreated diabetes is an increased risk for fungal infections. Diabetes creates the perfect conditions for yeast and other fungal infections to thrive. High glucose levels in the blood make skin drier and make it harder for the body to fight off infection. There isn’t any one area that’s affected by these fungal infections. Jock itch, vaginal infections, athlete’s foot, and even ringworm might indicate diabetes.

Fungal infections are just one of many skin problems that people with diabetes may deal with. Another major risk is that high blood sugar levels make it hard for the body to heal itself. Scratching at dry skin might cause it to open up and those cuts may not heal as easily. It is important that people with diabetes check their feet and other areas of their skin regularly so open sores can be properly treated.

16. Yellowing of the Eyes Could Indicate Liver Problems or Pancreatic Cancer

The eyes are one of the easiest places to see jaundice, which shows up as yellowing around the white part of the eye. It also turns your mucous membranes yellow. Jaundice is caused by an excess of bilirubin, a yellow substance in the blood. Bilirubin is produced when red blood cells break down.

While jaundice may be caused by taking certain medications, alcohol use, or viruses, it may also indicate serious underlying problems. Jaundice sometimes indicates problems in the liver, gallbladder, or pancreas. It is also a symptom of some types of cancer and viruses including autoimmune disorders, the Epstein-Barr virus, and Hepatitis A, B, and C.

17. Dry Eyes is a Symptom in 50% Of People with Hepatitis C

Some people suffer from dry eyes as a result of allergies. However, people with allergies are aware of them and deal with them through their life. In people who don’t have allergies though, dry eyes may be cause for concern. One study published in the American Journal of Opthamology looked at visual symptoms of Hepatitis C and found that approximately 50% of those in the study had decreased tear production as a symptom.

Things like being out in the sun all day, not getting adequate sleep, and excessive crying might also cause dry eyes. Hepatitis C is one of the sneakiest diseases because it can take up to 10 years for symptoms to appear. When they do, earliest symptoms are minor and include muscle aches, nausea, fever, fatigue, and jaundice. If Hepatitis C goes untreated, it leads to more severe symptoms that can include easy bruising and bleeding, weight loss, appetite changes, swelling in the legs, confusion and drowsiness, and more. Fortunately, treatment for Hepatitis C has come a long way and many people have success being treated soon after they are diagnosed.

18. Sudden Vision Changes Could Indicate Diabetes or Glaucoma

The most common cause of needing glasses, contacts, or other corrective measures for your eyes is a refractive error. Think of your eye like the lens of a camera. To get perfect vision, the cornea and retina need to be lined up perfectly. People may need corrective measures at any age, especially if eye sight starts to get worse with age. When vision loss happens suddenly, instead of over time, it may indicate a dangerous underlying disease.

Vision loss happens suddenly as a result of several diseases, including diabetic eye disease, macular degeneration, and glaucoma. It may also happen from vascular occlusions in the eye or retinal detachment. Many of these conditions require immediate attention, so you should schedule with an eye doctor about your sudden vision changes as soon as you can.

19. Difficulty with Night Driving May Be Caused By Cataracts

If night-time driving is getting more difficult, it may be time to schedule an appointment with the eye doctor. Problems like having difficult seeing, blurriness, seeing halos, or experience intense glare might indicate a cataract. Cataracts are a clouding of the lens over the eye, which causes vision to worsen even more than they do with age.

While cataracts are more common in people over 50, they can happen to anyone. Radiation treatment, long-term exposure to the sun, eye injury or surgery, diabetes, and even mental health medications and steroids can cause cataracts. Fortunately, people with cataracts usually have it treated with out-patient surgery. In most cases, it’s successful. In addition to the symptoms above, people with cataracts may also experience prescription changes in glasses, difficulty seeing in bright sunlight, double vision, or changes in the way they see colors.

20. Skin Tags Around the Eyes May Indicate High Cholesterol

Sometimes, skin tags are a condition called xanthelasma. This condition produces yellowish colored skin tags, generally around the eyes. The skin tags are caused by fatty deposits. Sometimes, xanthelasma is also an early sign of high cholesterol. When cholesterol levels are high, the fatty deposits in the blood pass through the skin and form the skin tag.

Managing cholesterol is important because it causes narrowing of the arteries, which lead to many other health problems. High cholesterol has been linked to peripheral artery disease, high blood pressure, type 2 diabetes, heart disease, and stroke. Eating the right types of fat and including whole grains in your diet are two ways that you can improve levels of cholesterol in the blood. This includes food sources like fish, avocado, and olive oil.

21. Increased Hair Loss or Dryness May Be a Vitamin Deficiency

Does your hair stay dry and brittle, or break off, regardless of how often you condition it? People with extreme hair dryness may also have a vitamin deficiency. Hair is made up of proteins and it’s overall health/moisture level is affected by things like proper nutrition. There are a number of vitamin and mineral deficiencies that may result in hair breakage, including Vitamin D, zinc, iron, and selenium. For people who experience hair loss, not eating enough protein may be to blame.

Maintaining a healthy diet is one of the cornerstones of good health. When your body is taking in the macro-nutrients it needs like healthy fats, proteins, and carbohydrates, as well as all the important vitamins and minerals, it has the foundation that it needs to stay healthy.

22. Underlying Disease May Result in Fingernail Changes

Your fingernails and toenails can tell you a lot about your body. Color changes like a blue-ish tint indicates poor circulation and that there is not enough oxygen in the blood, while white nails are likely from diabetes or liver disease. Pale-colored nails have also been linked to anemia, while nails that are half-pink and half-white have been linked to kidney disease.

There are also several other fingernail changes that indicate poor health. Yellowing may be caused by smoking or wearing red nail polish without a base, but it also may be caused by rheumatoid arthritis or lung disease. Pitting of the nails could indicate alopecia areata, atopic dermatitis, or even psoriasis. A dip in the nail with a “spoon-shape” is linked to low levels of iron, which might indicate that a dietary change is needed or that there are underlying digestive problems.