Meralgia paresthetica occurs when the lateral femoral cutaneous nerve is pinched, also known as compression. The nerve supplies feeling to the surface of the outer thigh. The nerve only affects sensation and doesn't impact your ability to use your leg muscles.
In most people, this nerve passes through the groin to the upper thigh without trouble. But in meralgia paresthetica, the lateral femoral cutaneous nerve becomes trapped. Often the inguinal ligament pinches the nerve. This ligament runs along the groin from the stomach to the upper thigh.
Common causes of this compression include any condition that increases pressure on the groin, including:
- Tight clothing, such as belts, corsets and tight pants.
- Obesity or weight gain.
- Wearing a heavy tool belt.
- Pregnancy.
- Fluid accumulation in the abdomen causing increased abdominal pressure.
- Scar tissue near the inguinal ligament due to injury or past surgery.
Nerve injury also can cause meralgia paresthetica. Nerve injury can be due to diabetes, trauma after surgery or seat belt injury after a motor vehicle accident.