Dr Phil: My teenager gets lightheaded when she stands up

Pic: iStock

My teenage daughter often gets lightheaded when she stands up quickly. Her face also turns deathly white whenever this happens. It passes quickly and doesn’t seem to affect her. Should I be worried?

Several factors can cause lightheadedness and pallor, but usually this is nothing to worry about.

Let’s start with some background questions.

Have other people in the family had symptoms like this in the past, particularly older sisters, mum or dad’s family? If lightheadedness runs in the family, there is less likely to be anything to worry about.

The next area to consider is the impact it is having on your daughter. Are the episodes happening often and curtailing her interaction with normal activities with her peers? Does she faint when it happens? Does she feel generally unwell afterwards and have to rest?

The answers go a long way to figuring out if you should be worried.

I note in your case that the symptoms pass quickly and don’t upset her, which is reassuring.

A lightheaded sensation happens when the blood pressure in the brain drops.

When we move from lying down or sitting to standing up, blood pressure has to rise to keep the blood flow to our brain constant.

A large number of systems (circulatory, nervous, hormonal, and muscular) work together to make sure this happens, and it is one of the adaptations that sets us apart from four-legged mammals. This complex and rapidly acting system can sometimes become less efficient, leading to a drop in blood pressure when we change posture.

Feeling lightheaded is a symptom most people will have experienced at some stage, and up to 25% of the population will lose consciousness (faint or syncope in medical speak). This means a large proportion of the population will have milder symptoms or “pre-syncopal symptoms”.

These symptoms are commonly made worse by not drinking enough fluids, standing for extended periods, overheating, or strong emotional stimuli (fear being the most common). Lightheadedness is also more likely to happen during puberty, particularly during a growth spurt.

I would encourage your daughter to ensure she is drinking enough fluids and not waiting until she is thirsty. Check she is eating enough, as sometimes lightheadedness is seen in young women restricting their food intake. If your daughter does not eat meat, it is a good idea to get her iron levels checked.

Regular exercise can help, along with sufficient sleep.

Red flags would be prolonged loss of consciousness (symptoms should resolve completely on lying down) and confusion after the episodes or injury caused by losing consciousness.

These are not usually mild and should be investigated immediately.

• If you have a question for Dr Phil Kieran, please send it to [e-mail].