M20.1: Hallux valgus (acquired)

You have a bunion.

The big toe consists of 2 toe bones. The two toe bones are connected to the metatarsal bone by a joint. The metatarsal bone is a long bone in the middle of the foot. The metatarsal bone and the toe bones of the big toe are normally connected to each other in a straight line.

With a bunion, over a period of time the metatarsal bone pushes outward towards the other foot. As a result, the ball of the foot bulges outward in that direction. The toe bones are displaced, too. With a bunion, the bones in the big toe point too much towards the adjacent toes.

A bunion can have a variety of causes. This is associated with various disorders or injuries, and a weakness in the muscles or tendons in the foot. Shoes that are too narrow can also contribute to causing a bunion.

A bunion can be painful. The skin over the bunion may be more callused than usual. The skin can also become inflamed there.


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the diagnostic confidence indicator.
Your doctor will assist you with any health-related questions and explain the ICD code to you in a direct consultation if necessary.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).

Further articles

Hallux valgus

Hallux valgus is also known as a bunion and is one of the most common foot deformities. Treatment is only needed for the deformity if it causes problems.