There are several conditions that can affect the feet:

Fungal infections

A contagious condition caused by a fungus called Tinea pedis, athlete’s foot flourishes in the warm, moist environment between the toes. It is often picked up from damp changing rooms and swimming pool floors.
Symptoms usually start between the fourth and fifth toes and the skin appears red and itchy, later becoming white, inflamed and weepy. It may also crack and peel.

Although not a serious condition, if left untreated athlete’s foot can spread to other areas of the foot and toenails.

If infection spreads to the nail, it may look thickened or discoloured at first. If the infection gets worse, white or yellow patches can appear where the nail has come away from the nail bed. The nail may also become soft and crumble and the skin next to it may be inflamed or scaly.

Left untreated, the infection can destroy the nail and nail bed and become painful.

Verrucas

A verruca (plantar wart) is caused by the human papilloma virus, which gets into the skin through a minor cut or abrasion. They appear as flattened, discreet lesions, usually on the ball of the foot, the underside of the big toe or the heel, either alone or in clusters. Multiple small black spots may be visible on the verruca, which are caused by bleeding in small blood vessels. Verrucas can be tender when squeezed and may cause discomfort when walking.

Corns and calluses

Corns are caused by rubbing or pressure from ill-fitting shoes. Hard corns are layers of dead skin that build up on the tops of toes and the outside of the little toes. The base of the corn is on the skin’s surface with the tip pointing inwards, pressing on nerve endings and causing pain. Soft corns are white, rubbery lumps found between the toes.

Calluses are caused by friction and pressure when the skin rubs against shoes or the ground. These have no centre and are less sharply defined than corns. They commonly appear on the ball of the foot, outside of the big toe and the sides of the heel. They produce a burning sensation, are yellowish in colour and are hard and rough.

Cracked heels

If the skin on the heels is particularly dry, it becomes thickened, hard and less flexible. When walking, pressure is put on the heel, causing the skin to stretch and spread out. If the skin is too inflexible to stretch, it will crack. Symptoms include dry, scaly areas of skin and vertical cracks or splits in the heel. In severe cases, the cracks may bleed or become inflamed or infected. Dry skin worsens with age as the skin loses elasticity and moisture.

Bunions

A bunion is a bone deformity of the joint at the base of the big toe. The toe will point inwards and force the bone to stick out. The cause is unknown but is thought to be linked to family history and wearing ill-fitting shoes can worsen the condition. 

Heel pain

The most common cause of heel pain is plantar fasciitis – inflammation of the plantar fascia, which is a tough band of connective tissue that supports the arch of the foot and also acts as a shock absorber. It is often described as a stabbing or aching pain about 4cm forward from the heel, although it can occur anywhere on the underside of the heel. It may be tender to touch and is often worse when walking first thing in the morning or after long periods of rest. Plantar fasciitis usually goes away with time but steps can be taken to ease any discomfort.