A bump on the bottom of your foot can be a source of concern. Many factors can contribute to these growths, some harmless and others requiring medical attention. Understanding common causes can help you determine when to seek professional medical advice.
Common Types of Foot Bumps
A common cause of bumps on the bottom of the foot is a plantar wart, resulting from human papillomavirus (HPV) infection. These warts often appear as small, rough growths, sometimes with tiny black dots (clotted blood vessels). They typically form on weight-bearing areas like the balls or heels, and pressure from walking can cause them to grow inward and become painful. HPV enters the skin through small cuts or breaks, and while generally not a serious health concern, they can cause discomfort.
Thickened skin, known as calluses and corns, frequently appear on the soles of the feet due to repeated friction or pressure. Calluses are broad, hardened areas of skin, usually less painful than corns, forming on weight-bearing areas like the heels and balls. Corns are smaller, raised bumps with a dense core that can be quite painful when pressed, often developing on or between toes. Both are the body’s protective response to irritation, with ill-fitting footwear being a common cause.
A plantar fibroma is a non-cancerous growth developing in the arch of the foot, arising from the plantar fascia ligament. These firm nodules are typically small and may not cause pain initially. However, as they grow or with pressure, they can lead to discomfort, feeling like a small stone in the shoe. While the exact cause is unknown, genetics and repetitive trauma may play a role.
Ganglion cysts are fluid-filled sacs that can form near joints or tendons in the foot. These cysts can vary in size, feeling soft or firm, and may be movable under the skin. Although their precise cause is not fully understood, they are linked to injury, repetitive stress, or irritation of nearby tendons or joints. While often harmless, they can cause pain if they press on nerves or tendons.
Bursitis is the inflammation of a bursa, a small fluid-filled sac that cushions bones, tendons, and muscles around joints. When a foot bursa becomes inflamed due to repeated stress or injury, it can result in a soft, tender lump. This condition can cause pain and difficulty with movement.
Bone spurs, or osteophytes, are bony growths that can form on bones, including the heel bone. While not always visible as a distinct bump, they can cause localized pain and may be felt as a hard area. They are often associated with conditions that stress foot bones and joints.
Morton’s neuroma can feel like a lump or mass in the ball of the foot, typically between the third and fourth toes. This condition involves a thickening of the nerve tissue, leading to symptoms like burning pain, tingling, or numbness. It often feels as if one is walking on a pebble or marble.
When to Seek Professional Medical Advice
While some foot bumps may be harmless, certain signs indicate the need for professional medical evaluation. If a bump causes persistent or worsening pain, or changes in size, shape, or color, seek attention. Signs of infection, such as redness, warmth, pus, or fever, require immediate medical assessment. If the bump makes walking difficult, causes numbness or tingling, or is growing rapidly, seek advice. Additionally, if the bump bleeds or oozes, or if you have underlying conditions like diabetes or compromised circulation, timely medical intervention is important.
Diagnosis and Treatment Approaches
Diagnosis
Diagnosis typically begins with a thorough clinical examination, including visual inspection and palpation, and a detailed patient history. Imaging studies like X-rays may assess bone structures, especially if a bone spur is suspected. Ultrasound can visualize soft tissue masses like cysts, while magnetic resonance imaging (MRI) provides detailed images of soft tissues and nerves. If malignancy is suspected, a biopsy may be performed.
Treatment
Treatment approaches vary widely depending on the diagnosis. Conservative measures often include observation, footwear modifications, padding or orthotics to relieve pressure, and topical medications. Injections, such as corticosteroids, may be used for inflammation. Surgical removal is typically considered for persistent, painful, or problematic bumps that do not respond to other treatments.