People who stand up and suddenly feel they might fall over again usually think about blood circulation as a possible cause, but the problem could also be due to shaky legs, according to experts.

The so-called orthostatic tremor usually appears at around age 60, and it is often not properly diagnosed, says the German Professional Association of Neurologists.

Affected people tend to develop some anxieties. They feel as though they want to permanently sit down or lean against something to stabilize their circulation, even though their instability may be due to something completely different.

A feeling of instability while standing that goes away when walking or sitting down is a typical symptom of orthostatic tremor. The tremor itself is often not visible, although neurologists can measure the electrical activity produced by muscles in a special test.

According to neurologists, many patients are relieved to find out the real cause of their symptoms. In serious cases, orthostatic tremor can be treated with anti-epileptic drugs.