You may never visit a podiatrist unless you’ve got a bunion, corn or planter’s wart, but annual checkups should include the doctor taking a look at your feet. Seems feet can provide the doctor with a lot of information about your health.

If you’ve had Achilles tendonitis or a bunion, you may see a podiatrist from time to time, but for most of us without any obvious foot issues, you probably don’t think twice about your feet—until there’s a problem. However, your doctor should be taking a cursory peak at your feet during an annual exam simply because there’s a lot of information to glean from feet.

Who knew? Seems feet may be like muddy windows into your health. Here’s a few foot problems that may reveal health issues:

1. If any part of your feet are numb, you should make an appointment with your physician right away. Podiatrists perform nerve tests to check a patient’s sharp and dull foot sensations. People with decreased sensation may have a peripheral neuropathy, which can signal diabetes since high sugar impacts the nerves, especially in the foot, leaving them less sensitive to touch.
2. Tipped up toes. Any change in the shape of your toes could be a red flag. Feet that have tipped up toes, called digital clubbing, may be a sign of a pulmonary or lung problem, a gastro issue like Crohn’s disease or even heart disease. Clubbing is an ancient and important clinical sign of health and your doctor can run some tests to make sure your tipped toes aren’t a sign of anything serious.
3. Burning sensation in feet. A burning-like pain in your feet may also signal a neuropathy, a dysfunction of the nerves that can be caused by a number of illnesses such as diabetes, vitamin deficiency or side effects from medicine. Talk to your doctor if you experience any burning-like foot pain to rule out diabetes and other health issues.
4. Painful, swollen big toe. A sign of gout, a kind of arthritis caused by the buildup of uric acid from the diet, especially wines, cheeses or red meat, gout happens when the body overproduces or under excretes uric acid and causes the big toe to swell and become red hot and painful. Gout affects 8.3 million Americans with obesity, weight gain, excessive alcohol intake and age. Cortisone injections, a preventative diet and medication can help.
5. Charley horse or cramps. Charley horses or extreme cramps in your lower legs or feet are involuntary muscle cramps caused by muscle spasms. They may be a result of dehydration, low potassium, poor circulation and other causes. Eating a banana before exercise and hydrating by drinking plenty of water may help, as can a routine of stretching or massage. If you experience a lot of foot cramping, talk to your doctor about other treatments.