Plantar fasciitis is a condition that many often associate with middle age, but certain hobbies -- like running -- can lead to this debilitating heel pain showing up much earlier in life.
The condition usually shows up as a serious, sharp pain at the heel. It's most severe first thing in the morning but improves throughout the day. Spending long periods standing or sitting in one place can also aggravate it.
The underlying cause is too much stress on the connective tissue (and possibly a nearby muscle) that runs from the heel along the bottom of your foot. Surgery can fix it, but most runners can avoid or remediate the problem by wearing properly supportive running shoes and using shoe inserts made for this purpose [source: Mayo Clinic]. In the short term, rest, foot and calf stretches, and anti-inflammatory medicine can help.