Doctors don't know the exact cause of rosacea. Some doctors think rosacea happens when blood vessels expand too easily, causing flushing. People who blush a lot may be more likely to get rosacea. It is also thought that people inherit the likelihood of getting the disease.
Though not well-researched, some people say that one or more of these factors make their rosacea worse:
- Heat (including hot baths)
- Heavy exercise
- Very cold temperatures
- Hot or spicy foods and drinks
- Drinking alcohol
- Emotional stress
- Long-term use of steroids on the face.
People with rosacea and pimples may think the pimples are caused by bacteria. But no one has found a clear link between rosacea and bacteria.