The cause of pain on the lateral side of the foot may be related to shoes, but generally it can be relieved by changing pairs of shoes. If the pain does not change or worsens, you should doubt the following problems.
Jones fracture
is also called the fifth metatarsal bone fracture. The basement of the small toe metatarsal was "unconsciously" fracture. See the figure below.

This fracture is also called a fatigue fracture. A crack as thick as a hair appeared on the bone, which occurs in a weak position of the fifth metatarsal bone. Injury or fall is prone to injury. Excessive exercise and repeated stress-bearing stress are very likely to occur. Fatigue fractures are not as bloody as open fracture . Instead, patients may only feel slight soreness at the beginning. Washing feet at night will find that there is a little swelling on the side of the foot, and it will not even swell. If you are not careful, the pain will gradually worsen with the movement. The blood supply at this position is insufficient, and the damage is not easy to heal, which may eventually cause bones to be non-contiguous ( fracture does not heal ) or even osteonecrosis .
If you are walking or exercising normally, your weight will cause pain and you cannot bear weight. You should be alert. If you do not relieve it for a week, you should seek medical attention, even if the swelling is mild or there is no swelling.
Treatment method is based on the degree of dislocation of the fracture, and slight braking rest. In severe cases, it is necessary to fix the gypsum for several weeks, and in very severe cases, surgery is required.
Pervix tendonitis
The tendons from the calf to the outside of the foot may also have problems. The tendons are similar to ropes, connecting muscles and bones together so that the legs and feet can move in a specific direction. Once the tendon becomes inflamed or torn, it can also cause pain on the outside of the foot, but the location of the pain is different from the fifth metatarsal fracture, and the range is larger.

This pain generally follows the tendon and manifests as pain on the feet, ankles, and the lateral calf. It may be caused by acute injuries or repeated strains. Patients often have no injuries or sprain their ankles, but the pain and swelling on the lateral aps will aggravate over time. Peroneal tendonitis may develop into a tendon tear. If the tendon is partially or completely torn, the following symptoms will occur:
- The ankle is weak or unstable.
- Severe pain on the outside of the foot and ankle.
- There is a sharp and snappy feeling on the tendon.
People with high arches are more likely to suffer from peroneal tendonitis because they are used to putting their weight on the outside of their feet. This accelerates the strain, inflammation and even tear of the tendon. This disease is easily misdiagnosed. X-ray alone may not be enough. It also requires nuclear magnetic resonance to determine whether it is a fracture or a tendon tear.
Sinus tarsal syndrome
The pain location of sinus tarsal syndrome is easier to distinguish, mainly concentrated around Ankle joint , with clear tenderness, and most of it occurs after spraining ankle. A few are related to foot deformities, Gout arthritis and rheumatoid arthritis. Common symptoms include stiff ankle, unstable, pain on the back of the feet when walking or standing, in addition, including:
- Pain when the feet are inward or outward.
- When carrying weight, your feet or ankles feel unstable.
- has difficulty walking on uneven surfaces such as grass or gravel.
- swelling and bruising.
However, it should be noted that this disease occurs together with spraining ankle. Some patients treat it as spraining ankle. As a result, the chronic pain cannot be relieved for several years. It is found that it can only be treated with conservative treatment for several weeks. If it is delayed for too long, it may require minimally invasive cleaning surgery.

Medical science, for reference only.