This condition, officially called primary orthostatic hypotension, is very common and is usually not a sign of a serious underlying problem.
It simply means that when you go from lying down or sitting to standing, your blood pressure drops and you feel a little lightheaded for a moment. This is because blood pools temporarily in your legs when you stand up, and your body takes a moment to compensate by squeezing blood out of the large veins in your legs and increasing your heart rate slightly. Dizziness can also occur after you eat a meal, because digestion diverts blood flow and can lower your blood pressure.
If your dizziness when changing positions is mild or occasional, some practical steps you can take to prevent it are:
- Check your medications: Many medications can lower blood pressure. That contributes to a large number of cases. It may help to reduce the dose or stop taking medications you don’t really need—after consulting with your doctor, of course.
- Drink enough water: Another common culprit is dehydration. Your blood is mostly water, and the volume in your system can decrease overnight, lowering your blood pressure. This helps explain why dizziness when getting out of bed is so common. Drinking lots of water before bed isn’t the best solution, as it can cause you to run to the bathroom at night. Wait until you’re up and walking around normally to start drinking enough water, and stay hydrated throughout the day.
- Get up slowly: After sleeping, sitting for a long time, or eating a large meal, stand up slowly. It may help to tighten your leg muscles before standing to push the accumulated blood back into your system.
- Change your eating habits: If dizziness occurs after meals, try eating smaller, more frequent meals. It can also help to limit the amount of fast-digesting carbohydrates you eat at one sitting, such as white bread and other foods made from highly refined flour, white rice, potatoes, and sugary drinks.
- Exercise: A little light exercise in the morning can also help your blood flow and increase your blood pressure. Also, avoid standing or sitting for too long, as this increases the amount of blood pooling in your legs.
