Also in this week's column:

• Does drinking alcohol really keep you warm?
• Can you judge someone's personality by the shape of their ears?
• What is a fistula?

Asked by Liz Downes of Las Vegas, Nevada, USA

There are all sorts of unusual forms of headaches that most people have never heard about. The post-lumbar puncture headache is one of them. This form of headache occurs after one has a spinal tap (lumbar puncture).

According to the Mayo Clinic, headaches of this kind are often accompanied by stiffness in the neck, ringing in the ears, light sensitivity, nausea, and hearing impairment. The headache generally develops within a week after the spinal tap and typically resolves within a week. Such a headache can be debilitating.

A post-lumbar headache may start when one stands up and stop when one lies down. There is some debate as to what percent of patients who have a spinal tap also develop a post-lumbar puncture headache.

An article by Heidi Moore in Pulmonary Reviews in December 2000 estimated that the figure was "[N]early a third or more". But a more recent review by Dr R Gaiser of the University of Pennsylvania and published in Current Opinion in Anaesthesiology in June 2006 suggests the figure is "approximately 50 per cent".

Males are less likely to suffer post-lumbar puncture headaches than females. This is according to a team of doctors from Johns Hopkins University, led by Dr C L Wu, and published in Anaesthesiology in September 2006.

The lumbar region is the lower back. Anatomically, it is located at the back between and the thoracic vertebrae and the sacrum. The lumbar region is sometimes referred to somewhat inaccurately as the loins. "Lumbar" is from the Latin lumbus and means "loins".

Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to s.juan@edfac.usyd.edu.au

Related stories

• What happens when you are executed by electrocution? (20 October 2006)
• Can stun guns and tasers cause death? (13 October 2006)
• What are the scientific reasons for having sex? (6 October 2006)
• Can flossing your teeth prevent a heart attack? (29 September 2006)
• Could you be addicted to the internet? (22 September 2006)
• Are there people with no sense of smell? (15 September 2006)
• Can you become intoxicated by the power of suggestion? (8 September 2006)