A bulge on the side of the ankle can be concerning. While often harmless, it may signal an underlying issue. Its appearance varies, sometimes with pain, sometimes without, depending on its origin.
Potential Causes of Ankle Bulges
A common reason for an ankle bulge is a ganglion cyst. These non-cancerous, fluid-filled sacs typically form near joints or tendons. They appear as smooth, soft or firm lumps that can change size. While generally harmless, they may cause discomfort if they press on a nerve or hinder joint movement.
Ankle sprains or ligament injuries frequently cause swelling that appears as a bulge. When ligaments are stretched or torn, fluid and blood accumulate, causing localized swelling and bruising. This bulge is usually accompanied by pain, tenderness, and difficulty bearing weight, especially after a twisting motion.
Peroneal tendinitis can also result in an ankle bulge. The peroneal tendons run along the outside of the lower leg and behind the outer ankle bone, aiding ankle stability and foot movement. Inflammation, often from overuse or improper footwear, causes swelling and pain along their path. This creates a visible, typically tender bulge.
Osteoarthritis or the development of bone spurs might also contribute to a hard bulge on the ankle. Osteoarthritis is a degenerative joint disease where the cartilage cushioning the ends of bones wears down over time. In response to this degradation, the body can form bony growths called osteophytes, or bone spurs, around the joint. If these spurs develop on the side of the ankle, they can create a firm, immovable lump, potentially causing stiffness and pain with movement.
Bursitis is another potential cause, involving the inflammation of bursae, which are small, fluid-filled sacs that cushion bones, tendons, and muscles near joints. If a bursa on the side of the ankle becomes inflamed, often due to repetitive motion or direct pressure, it can swell and form a soft, tender bulge. This condition typically causes localized pain that worsens with movement or pressure on the affected area.
Gout, a form of inflammatory arthritis, can also manifest as a bulge on the side of the ankle. It occurs when urate crystals accumulate in a joint, leading to sudden, severe attacks of pain, swelling, redness, and tenderness. While gout commonly affects the big toe, it can also impact other joints, including the ankle, causing a visibly swollen and inflamed area that can resemble a bulge. The affected area often feels warm to the touch.
In some instances, a lipoma might be the source of an ankle bulge. A lipoma is a non-cancerous growth of fatty tissue that develops slowly under the skin. These benign tumors are typically soft, rubbery, and movable when pressed, and they are usually painless. They can occur anywhere on the body, including the ankle, presenting as a soft, distinct bulge that feels different from other types of swelling.
When to Consult a Doctor and Initial Care
Consult a healthcare professional if an ankle bulge presents with certain symptoms. Immediate medical attention is warranted for signs of infection.
When to Consult a Doctor
Severe pain or inability to bear weight.
Rapid increase in size or sudden appearance without clear cause.
Redness, warmth, or fever alongside the bulge.
Numbness or tingling in the foot or toes.
Noticeable ankle deformity.
Bulge does not improve with rest or worsens over time.
Recurrent bulges.
These symptoms can indicate more serious underlying conditions that require specific diagnosis and treatment.
While waiting for a medical appointment or for mild cases, initial self-care steps can help manage discomfort. The R.I.C.E. protocol, which stands for Rest, Ice, Compression, and Elevation, can be beneficial. Resting the affected ankle helps prevent further injury, while applying ice can reduce swelling and pain. Gentle compression with a bandage can also help control swelling, and elevating the ankle above heart level assists in fluid drainage. These measures are temporary and do not replace a professional medical diagnosis.