Understanding Lateral Foot Pain: 5 Common Causes

Experiencing pain on the outer side of your foot, known as lateral foot pain, can occur before, during, or after activities such as walking, running, or even standing. This pain can range from mild to severe, affecting your ability to move or participate in daily tasks like exercising, working, or simply standing.

While lateral foot pain is not as common as heel or toe pain, it can still disrupt your life, especially if the pain is sharp, burning, or stabbing. Below are some common symptoms you may notice with lateral foot pain:

• Swelling
• Tenderness
• Difficulty standing or walking
• Instability in the foot
• Increased likelihood of ankle sprains
• Pain on the outer side of the ankle

Given that lateral foot pain can have several different causes, it may be difficult to pinpoint the exact source. If rest does not improve your condition or if the pain worsens, it's important to see a doctor. A healthcare provider can diagnose the issue and recommend the best treatment. Let’s take a look at some of the most common reasons for lateral foot pain:

1. Stress fractures

Stress fractures are a common cause of lateral foot pain, often resulting from overuse. These tiny fractures in the bone typically affect athletes, especially teenagers and young adults in their 20s. People who suddenly increase their physical activity, wear unstable shoes, or lack essential nutrients like calcium and vitamin D are also at risk.

Because stress fractures tend to worsen over time, it’s essential to seek medical attention early. By the time many people see a doctor, surgery may be required to treat the fracture.

2. Achilles tendinitis

The Achilles tendon is the largest and strongest tendon in the body, connecting the calf muscles to the heel bone. While Achilles tendinitis commonly causes pain at the back of the heel, it can also contribute to pain on the outer side of the foot. This condition occurs when the tendon becomes inflamed, often due to overuse or repetitive stress.

People with Achilles tendinitis may also experience stiffness, swelling, and tenderness, making it difficult to move the foot or ankle.

3. Arthritis

Arthritis is a condition that leads to inflammation and pain in the joints and can be a common cause of lateral foot pain. Two types of arthritis are especially known for causing pain in this area:

• Osteoarthritis: Known as wear-and-tear arthritis, osteoarthritis occurs when the cartilage that cushions the joints wears down, causing pain and stiffness.
• Rheumatoid Arthritis: This autoimmune condition causes the body’s immune system to attack the lining of the joints, leading to swelling and damage to the bones, cartilage, and other joint structures.

Arthritis-related pain on the outer side of the foot is often accompanied by warmth and redness in the affected joint. The pain may worsen with movement or activity.

4. Peroneal tendonitis

Peroneal tendonitis is one of the more common causes of lateral foot pain, especially in athletes. This condition involves inflammation in the peroneal tendons, which run along the outer side of the foot. Peroneal tendonitis tends to develop gradually, with pain slowly increasing over time.

Long-distance runners and other athletes are particularly prone to peroneal tendonitis, though it can also occur in people with high arches, muscular imbalances, or previous ankle injury.

5. Ankle sprains

Ankle sprains are one of the most common causes of pain on the outer side of the foot. This injury often occurs during activities that involve sudden changes in direction or movements that cause the foot to roll or twist, such as basketball, volleyball, trail running, or hiking on uneven terrain.

When the foot twists, it can tear the ligaments that support the ankle bones, causing pain. Ankle sprains are often accompanied by swelling, bruising, and tenderness. In severe cases, you might hear a popping sound when the injury occurs. It’s important to treat ankle sprains quickly, as failure to do so can lead to long-term issues such as chronic pain or weakness. Additionally, having one ankle sprain increases your risk of future sprains.