Yes. POTS (postural orthostatic tachycardia syndrome) can make the heart race after a person stands up. The heart rate rises because the body has trouble keeping blood moving normally while upright. A racing heartbeat may occur with dizziness, weakness, shaky feelings, or blurred vision and may ease when lying down. However, a fast heartbeat after standing can have other causes, so it should be checked if it keeps happening.
Why can POTS cause a racing heartbeat?
When you stand up, gravity causes some blood to move toward your lower body. Normally, the nervous system helps the blood vessels tighten and adjusts the heart rate to maintain blood flow to the brain and other organs. The heart rate may rise briefly as part of this normal response.
In POTS, the body's automatic control of heart rate and blood vessel function does not respond as expected to an upright position. The heart may beat faster than usual to help maintain circulation. According to the Cleveland Clinic's explanation of POTS, this condition can affect the body's ability to keep blood flow stable when a person moves from lying down or sitting to standing.
What does a POTS-related racing heart feel like?
The NHS guidance on postural tachycardia syndrome explains that symptoms may begin when a person stands and may improve after sitting or lying down. A racing heartbeat may feel like pounding, fluttering, or a strong awareness of the heartbeat. Other experiences that can occur alongside it include:
- Dizziness or lightheadedness after standing.
- Feeling weak, shaky, or unusually tired.
- Blurred vision or difficulty concentrating.
- Shortness of breath or unusual sweating.
- Feeling close to fainting or occasionally fainting.
Symptoms can begin immediately or develop over the first few minutes of standing. They may become more noticeable after prolonged standing, in hot environments, during illness, or when fluid intake has been inadequate. The pattern can also vary from one day to another.
How much should the heart rate increase with POTS?
A small, temporary increase in heart rate after standing is normal. POTS involves a more sustained increase accompanied by symptoms related to being upright. According to the National Institutes of Health (NIH), clinicians may consider an increase of more than 30 beats per minute in adults or at least 40 beats per minute in people younger than 20 within 10 minutes of standing, without a major drop in blood pressure.
These figures are part of a broader clinical assessment, not a home test for diagnosing POTS. Healthcare professionals also consider how long symptoms have been present, whether they occur regularly while upright, whether blood pressure falls, and whether another condition explains the increased heart rate. A single high reading from a smartwatch or pulse monitor cannot establish the diagnosis.
Can something other than POTS cause a racing heart after standing?
Yes. Several conditions and circumstances can produce a similar response. The American College of Cardiology's CardioSmart guidance on diagnosing POTS highlights the importance of considering other explanations before attributing symptoms to this syndrome.
- Dehydration: Not having enough fluid in the body can affect circulation and heart rate.
- Anemia: A low red blood cell count or reduced hemoglobin can contribute to a rapid heartbeat.
- Thyroid problems: An overactive thyroid can increase heart rate.
- Infection or fever: These can cause the heart to beat faster than usual.
- Medicines or stimulants: Certain medicines, caffeine, and other stimulants can affect heart rate.
- Heart rhythm problems: An abnormal rhythm can cause a racing or irregular heartbeat.
- Blood pressure changes: A fall in blood pressure after standing can cause dizziness and other symptoms.
These possibilities can overlap with POTS, and more than one factor may contribute to symptoms. The relationship between the heartbeat and body position is useful information for a clinician, but it does not identify the cause by itself.
How do healthcare professionals assess a racing heart after standing?
Evaluation usually begins with questions about when the racing heartbeat started, how often it happens, how long it lasts, and whether it improves after sitting or lying down. A healthcare professional may also ask about fainting, recent illness, fluid intake, medications, and other health conditions.
Johns Hopkins Medicine's POTS guidance describes the use of a medical history, physical examination, heart rate and blood pressure measurements, and tests to investigate the cause. Depending on the situation, assessment may include:
- An active stand test: Heart rate and blood pressure are measured while lying down and after standing.
- An electrocardiogram (ECG): This records the electrical activity of the heart and helps assess its rhythm.
- Blood tests: These may help identify conditions such as anemia or thyroid problems.
- A tilt-table test: If needed, a monitored test measures how heart rate and blood pressure respond as the body is tilted upright.
Not everyone needs every test. The choice depends on the person's symptoms, medical history, examination, and initial findings. If the racing heartbeat is persistent, recurrent, worsening, or interfering with daily activities, arrange a medical assessment rather than assuming POTS is responsible.
What should you do when your heart races after standing?
If you develop dizziness or feel close to fainting, sit or lie down somewhere safe. Raising your legs while lying down may help you feel better. Once symptoms settle, change positions slowly rather than standing up abruptly. If you have already been diagnosed with POTS, follow the plan provided by your healthcare professional.
Do not begin a high-salt diet, substantially increase fluid intake, or change medication solely because your heart races when you stand. The appropriate approach depends on the cause of the symptoms and your overall health, including whether you have conditions that require limits on fluid or salt intake.
When does a racing heart after standing need urgent attention?
A fast heartbeat after standing is not always caused by POTS, and some accompanying symptoms need urgent evaluation. The NHS guidance on heart palpitations recommends emergency medical help when palpitations do not stop or occur with chest pain, shortness of breath, or fainting or a feeling of faintness.
Seek emergency care if these warning signs occur. Even without them, arrange a medical appointment if the racing heartbeat keeps returning, becomes more frequent, lasts longer than usual, or begins to affect everyday activities. A clinician can investigate the cause and determine whether POTS or another condition needs attention.