Warning signs that somebody may have Munchausen's syndrome include:

• frequent visits to hospitals in different areas,
• claiming to have a history of complex and serious medical conditions, yet there is little documentary evidence to support this; a common ruse is for people to claim they have spent a long time out of the country,
• symptoms that do not correspond to the results of tests,
• symptoms that get worse for no apparent reason,
• the person has a extremely good medical knowledge,
• the person receives very few, or no, visitors in hospital; many people with Munchausen's syndrome adopt a solitary lifestyle and have little contact with any friends of family,
• a willingness to undergo often painful or dangerous tests and procedures, and
• if confronted about their behaviour, they can become aggressive and will try to leave the hospital.

Patterns of behaviour in Munchausen's syndrome

There are four main ways in which people with Munchausen's syndrome can feign or induce illnesses, which are outlined below.

• Lying about symptoms - often they choose symptoms that are hard to disprove, such as having severe headaches or they may pretend to have a seizure or pass out.
• Tampering with test results - such as heating thermometers to suggest fever or adding blood to urine samples.
• Self-infliction - they may cut or burn themselves, poison themselves with drugs or an overdose of medication, or eat food that has been contaminated with bacteria.
• Aggravate pre-existing conditions - such as rubbing dirt or dog faeces into wounds to cause an infection, or reopen previously healed wounds.