Maybe you stand up too quickly or you haven’t eaten in a while and suddenly you're feeling dizzy or off balance. You’re lightheaded. Sometimes, lightheadedness isn’t anything to worry about. But other times, it could be a sign that something is wrong.
One of the things that could cause lightheadedness is hypotension, or low blood pressure. You’ve probably heard a lot about high blood pressure and its link to heart disease. You might not realize there are times when low blood pressure could be a problem, too.
What is low blood pressure?
“Blood pressure is a measure of the force on the walls of the arteries when the heart pumps blood into them,” said Hassan Beydoun, MD, a cardiologist with Banner – University Medicine.
Hypotension is when this force is too low. With hypotension, your organs might not get enough blood.
You have two measurements that tell you what your blood pressure is. The pressure when your heart beats is the first or top number, called systolic. The pressure when your heart is at rest between beats is the second or bottom number, called diastolic.
Blood pressure is measured in millimeters of mercury (mmHg). A normal blood pressure reading is around 120/80 mmHg. “Low blood pressure is less than 90/60 mmHg, or when you have an exaggerated drop in blood pressure and increase in heart rate when you stand up,” Dr. Beydoun said.
Symptoms of hypotension
Symptoms of low blood pressure include:
- Dizziness and lightheadedness: Feeling that the world around you is swaying or you aren’t steady on your feet. You may feel disoriented. “Low blood pressure causes lightheadedness simply because not enough blood and oxygen is reaching the brain,” Dr. Beydoun said.
- Fatigue and weakness: Your organs and muscles might not get enough oxygen, so you might feel tired or weak even when you haven’t exerted yourself very much.
- Fainting or almost fainting: Called syncope, you can faint or nearly faint when your brain doesn’t get enough blood flow or oxygen.
Causes of hypotension and lightheadedness
Different things can be making your blood pressure low or making you feel lightheaded. Some causes of hypotension include:
- Fast position changes: Orthostatic hypotension or postural hypotension happens when you stand up quickly and your blood pressure drops.
- Dehydration: When your body doesn’t have enough fluid, you don’t have as much blood volume, which can lower your blood pressure.
- Heart problems: An extremely low heart rate (bradycardia) or heart valve problems can prevent your heart from pumping blood effectively and cause hypotension.
- Heart-brain miscommunication: Neurally mediated hypotension happens when your heart and brain don’t communicate properly.
- Disorders affecting the endocrine system: Conditions like adrenal insufficiency (Addison’s disease) or low thyroid function (hypothyroidism) may cause hypotension.
- Severe infection (septicemia): Blood infection can cause inflammation that can affect your blood vessels and lead to low blood pressure.
- Blood loss: Losing a lot of blood due to injury, surgery or a medical condition can quickly lead to hypotension.
- Anxiety or panic attacks: Your breathing rate at these times can cause lightheadedness.
- Low blood sugar: A drop in blood glucose levels can cause a drop in blood pressure.
- Side effects of some medicines: Medications for some health conditions can cause hypotension.
- Heart attack, heart failure or stroke: These serious conditions can lower your blood pressure.
- Inner ear problems: Your inner ear manages your balance, so problems can cause dizziness and lightheadedness.
- Low iron levels in your blood: Anemia can keep your cells and organs from getting the oxygen they need.
Diagnosing hypotension
If you feel lightheaded sometimes, it might not be anything to worry about. But if your symptoms are more serious, talk to a health care provider.
“You should see a provider if you have dizziness, fainting, lightheadedness, blurred vision, palpitations, confusion, nausea or general weakness,” Dr. Beydoun said. It’s important to seek care if your symptoms make it hard to do your daily activities or affect your quality of life.
To diagnose hypotension, your provider may:
- Ask you about your symptoms, medical history and lifestyle.
- Monitor your blood pressure to see how it changes throughout the day.
- Evaluate the electrical activity of your heart with an electrocardiogram.
- Record your heart activity for a longer time with a Holter monitor, which may catch problems that don’t show up in a short exam.
- Test your blood for hormone levels, signs of infection and organ function.
- Perform a tilt table test, which checks how your blood pressure changes when you shift from a lying to a standing position.
Get immediate medical care if you have any of these symptoms. They could be signs of a serious or life-threatening problem:
- Chest pain
- Shortness of breath
- Confusion
- Loss of consciousness
- Severe injury or bleeding
Lifestyle changes
You can take some steps to manage hypotension:
- Stay hydrated since dehydration can cause low blood pressure. Drink plenty of water, especially if you’re exercising or you’re outside in hot weather.
- Eat small, low-carb meals to keep your blood sugar levels stable.
- Add more salt to your diet.
- When you stand up from sitting or lying down, go slowly. “That gives your body time to adjust to the change in position,” Dr. Beydoun said.
- Wear compression stockings to help the blood circulate up from your legs.
- Avoid alcohol and too much caffeine, which can cause a drop in blood pressure.
- Get regular exercise to help keep your cardiovascular system healthy.
- If possible, stop taking medications that are causing low blood pressure. Talk to your health care provider before stopping any medications.
Treatment options
Depending on what’s causing your low blood pressure, your provider may recommend treatments in addition to lifestyle changes. Some options are:
- Medications to regulate blood pressure and treat conditions that could be causing low blood pressure, such as fludrocortisone, midodrine and erythropoietin.
- Treatment for heart conditions.
- Managing endocrine disorders like adrenal insufficiency or hypothyroidism.
- Treating infections like septicemia.
The bottom line
If you have low blood pressure — less than 90/60 mmHg or a big drop in blood pressure when you stand up — it could cause lightheadedness and other symptoms. If it happens once in a while, it’s probably not a cause for concern. But if it’s affecting your life or you have other symptoms, you’ll want to see a health care provider.
Reach out to Banner Health to connect with a provider who can diagnose and treat lightheadedness and hypotension.
