Four things to think about before taking a commercial DNA test

Stacey Dooley helps people find answers to life-changing questions through the power of a DNA test in BBC Two's DNA Family Secrets.

And over 26 million of us around the world have already taken a DNA test. Here are a few things to bear in mind if you’re thinking of taking one yourself…

Once you take a commercial DNA test – particularly if you register with your full name – you become traceable within online genetic databases UNLESS you mark your results private. This means you could be contacted at any point in the future by a relative or just a curious stranger. In most cases it’s harmless, but something to bear in mind if you value your privacy.

DNA tests can have surprising and unexpected results. Not everyone gets the answer they’re hoping for. Best to be prepared that it could uncover something out of the blue. During the series, the contributors worked with experts who could help them iunderstand their test results and provide support.

The most common reason people take a DNA test is to find out about their ethnicity or ancestry. However, working out the exact location your ancestors may have come from is still a developing science and being upgraded all the time. It’s important to bear in mind your results may not be 100% accurate.

Some commercial DNA tests claim to be able to diagnose potential health issues. These results should be taken with a pinch of salt. If you’re concerned about a medical issue best to contact your GP.