Clues your feet give about your health, 15-16

15. Red flag: Toes that bump upward at the tips

What it means: When the very tips of the toes swell to the point where they lose their usual angle and appear to bump upward at the ends, it's called "digital clubbing" or "Hippocratic clubbing" after Hippocrates, who described the phenomenon 2,000 years ago. It's a common sign of serious pulmonary (lung) disease, including pulmonary fibrosis and lung cancer. Heart disease and certain gastrointestinal diseases, such as Crohn's disease, are also associated with clubbing.

More clues: Fingers can be clubbed as well as toes. It can happen in just some digits, or in all.

What to do: Treatment depends on the underlying cause, so report this serious symptom to a doctor. (Physicians are also well trained to look for clubbed digits during exams.)

16. Red flag: Shooting pain in the heel

What it means: Plantar fasciitis -- a fancy name for inflammation of a band of connective tissue (fascia) running along the bottom (plantar) of the foot -- is abnormal straining of the tissue beyond its normal extension.

More clues: The pain starts when you take your first steps in the morning and often intensifies as the day wears on. It's usually concentrated in the heel (one or both) but can also be felt in the arch or in the back of the foot. Running and jumping a lot can cause it, but so can insufficient support. You're at risk if you go barefoot a lot or wear old shoes or flimsy flip-flops, have gained weight, or walk a lot on hard surfaces.

What to do: If pain persists more than a few weeks or seems to worsen, have it evaluated by a podiatrist. Stick to low shoes with a strong supportive arch until you get further advice and treatment (which may include anti-inflammatory drugs and shoe inserts).