A wide range of conditions can cause bumps underneath the skin on the foot. Diabetics must pay attention to any abnormalities on their feet as blood circulation becomes disrupted. Ill-fitting shoes can lead to uncomfortable lumps and bumps. According to Medline Plus, most bumps are benign but should be checked for signs of infection or malignancy if they don't respond to home remedies.
A callus that forms on the big toe can interfere with walking when it becomes too painful. According to the Podiatry Network, the bump may result from having your big toe squeezed so that it doesn't move when you walk. This movement limitation eventually leads to a formation of hardened skill cells that cause the lump to develop on the bottom of the toe. The bone responds by enlarging as a result of the excessive pressure and worsens the discomfort.
The most effective way to test for the condition is to try to bend your big upward. If it does not respond to gentle pressure with your hand, you may have developed a lump under the skin that has moved beyond a simple callus and requires medical attention. The bony lump under the skin can ulcerate in people with diabetes. More lumps may appear under the skin on top of the toe from the continued abuse. Arthritis also can develop in the toe joint over time.
The bone that connects the toes to the ball of your foot may be misaligned and cause bumps under the sole of the foot that are not typically calluses as well. Over time, the weight-bearing pressure causes painful bumps to form that may cause you to walk improperly to avoid placing additional pressure on the bumps. The lumps often can be removed and should be checked for ulcers or infection.
Orthotics are available as inserts in the shoes that provide soft padding to alleviate the pain when you walk. Foot irregularities caused by internal bone deformities typically do not respond to surgical interventions, according to the Podiatry Network. Plantar warts often can be treated with over-the-counter medications. Skin cancer bumps that form under the skin on the foot usually are accompanied by topical bumps that become crusty and change shape and size over time. The tops of the feet are especially vulnerable to ultraviolet exposure that can lead to cancer and must be treated with surgery and follow-up drugs and radiation.
Tumors that commonly form in the arch of the foot are called plantar fibromas and usually are not malignant. The bumps occur on the tendons and may be caused by an injury, although the exact cause often is unidentifiable, according to the Podiatry Network. When the tumors result as a side effect of taking certain medications, similar bumps may appear under the skin on your hands. Orthotics also are used to treat plantar fibromas to relieve the pressure.