Dry, flaky skin or lips
This is a common warning sign of dehydration. It may also indicate a more serious problem that affects sweat gland function, such as hypothyroidism (marked by insufficient levels of thyroid hormone) or diabetes, says Roshini Raj, MD, assistant professor of medicine at the NYU School of Medicine and author of What the Yuck?! Other signs of hypothyroidism include feeling cold, weight gain, and fatigue. Diabetes symptoms include extreme thirst, frequent urination, and blurry vision. Here are more signs of disease your skin can reveal.
Excess facial hair
Unwanted hair, particularly along the jawline, chin, and upper lip, could be a symptom of polycystic ovary syndrome, a hormone imbalance in which male hormone levels are elevated. (The condition may affect five million U.S. women of childbearing age.) Make sure you know the diseases doctors are most likely to miss.