Toenail fungus is an infection that gets in through cracks in your nail or cuts in your skin. It can make your toenail change color or get thicker. It can also hurt. Because toes are often warm and damp, fungus grows well there. Different kinds of fungi and sometimes yeast affect different parts of the nail. Left untreated, an infection could spread to other toenails, skin, or even your fingernails.

Ingrown toenails occur when the edges or corners of your nails grow into the skin next to the nail. Your big toe is most likely to get an ingrown toenail. You can treat ingrown toenails at home. However, they can cause complications that might require medical treatment. Your risk of complications is higher if you have diabetes or other conditions that cause poor circulation.

Plantar fasciitis (PLAN-tur fas-e-I-tis) is one of the most common causes of heel pain. It involves inflammation of a thick band of tissue that runs across the bottom of your foot and connects your heel bone to your toes (plantar fascia).

Plantar fasciitis commonly causes stabbing pain that usually occurs with your first steps in the morning. As you get up and move, the pain normally decreases, but it might return after long periods of standing or when you stand up after sitting.

Plantar fasciitis is more common in runners. People who are overweight and those who wear shoes with inadequate support also have an increased risk of plantar fasciitis.

Tendinitis is inflammation or irritation of a tendon — the thick fibrous cords that attach muscle to bone. The condition causes pain and tenderness just outside a joint. While tendinitis can occur in any of your tendons, it's most common around your shoulders, elbows, wrists, knees and heels.

A callus is a thickened area of skin on the foot caused by pressure and repeated rubbing, such as from a shoe or sock. The rubbing causes the skin to produce a layer of protective skin (a callus). Calluses vary in size and can become painful.

Hammertoe and mallet toe are foot deformities that occur due to an imbalance in the muscles, tendons or ligaments that normally hold the toe straight. The type of shoes you wear, foot structure, trauma and certain disease processes can contribute to the development of these deformities.

A hammertoe has an abnormal bend in the middle joint of a toe. Mallet toe affects the joint nearest the toenail. Hammertoe and mallet toe usually occur in your second, third and fourth toes.

You have flatfeet when the arches on the inside of your feet are flattened, allowing the entire soles of your feet to touch the floor when you stand up.

A common and usually painless condition, flatfeet can occur when the arches don't develop during childhood. In other cases, flatfeet develop after an injury or from the simple wear-and-tear stresses of age.

Flatfeet can sometimes contribute to problems in your ankles and knees because the condition can alter the alignment of your legs. If you aren't having pain, no treatment is usually necessary for flatfeet.

Ankle Sprain: Caused by stretching or tearing of one or more ligaments (structures that connect bones to bones). Most sprains result from accidental turning of the foot inward.

Tendonitis: An inflammation of a tendon caused by overuse. Tendons connect muscles to bones.

Fractures: Ankle injuries can sometimes result in fractures of the bones comprising the ankle joint. Many of these fractures can be treated without casting.

Stress fractures: Develop over time as a result of overuse of the ankle.

Diabetics are at high risk for complications of their feet. Some may have peripheral neuropathy, a type of nerve damage causing numbness, tingling, or pain. This lowers your ability to feel pain, heat, or cold. Diabetics may not notice a cut, blister, sore, or other problem. Small problems can become serious if they aren’t treated early.

Orthotics are special shoe or heel inserts a doctor prescribes that are custom-made specifically for you.

A doctor may prescribe orthotics to treat foot, leg, or back problems.

Corns are hard, thickened areas of skin that form as a result of friction or pressure on the skin that can become painful.

A heel spur is a pointed bony outgrowth of the bone of the heel (the calcaneus bone). Chronic local inflammation at the insertion of soft-tissue tendons or plantar fascia is a common cause of bone spurs (osteophytes).

Heel spurs can be located at the back of the heel or under the heel, beneath the arch of the foot. Heel spurs at the back of the heel are frequently associated with inflammation of the Achilles tendon (tendinitis) and cause tenderness and heel pain made worse while pushing off the ball of the foot.