The exact cause of bunions is unknown, but possible causes may include:
- genetics (family history)
- arthritis
- other conditions
- poorly fitting shoes
These possible causes are discussed in more detail below.
Genetics
If other members of your family have bunions, your risk of developing them is increased.
Arthritis
The types of arthritis thought to cause bunions are:
- rheumatoid arthritis - inflammation (swelling) and pain in the joints that results from the immune system attacking the lining of the joints
- gout - another common type of arthritis that causes painful inflammation in one or more joints
- psoriatic arthritis - a type of arthritis that is associated with the skin condition psoriasis
Other conditions
Several other conditions are thought to increase your chances of developing bunions. For example, conditions that are associated with loose ligaments (ligamentous laxity), flexible joints and low muscle tone could increase the likelihood of bunions developing. These conditions are listed below.
Neuromuscular conditions
- cerebral palsy - a neurological condition (of the brain and nervous system) that affects a child’s co-ordination and movement
- Charcot-Marie-Tooth disease - a group of genetic conditions that causes damage to the nerves outside the central nervous system
- multiple sclerosis - a neurological condition that can cause muscle weakness and balance problems
Connective tissue disorders
- Marfans syndrome - a genetic condition that affects the body’s connective tissues (which provide support and structure to other tissue and organs)
- Down’s syndrome - an uncommon genetic condition that can cause learning difficulties and distinct physical characteristics, including loose joints
Poorly fitting shoes
Poorly fitting shoes can contribute to the development of bunions. Bunions are rare in populations that do not wear shoes.
Wearing shoes that are too tight and do not fit properly is likely to make an existing bunion worse.
If your shoes are too tight, they may rub against your big toe joint. High-heeled shoes that are too tight will squeeze your feet, causing your big toe to remain in a bent position. This can stretch the toe, putting pressure on the nerves around it and leading to pain.
High heels also push most of your body weight forwards onto the front of your foot, which places considerable strain on your toe joints.
