Sudden Dizziness Standing Up? POTS Symptoms, Low Blood Pressure, and Dizziness Standing Up Explained

Sudden dizziness standing up can feel alarming, especially when it happens out of nowhere or keeps coming back. Many people wonder whether this could be a sign of Postural Orthostatic Tachycardia Syndrome (POTS) or simply low blood pressure.

What is POTS?

Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder of the autonomic nervous system that affects how the body regulates heart rate and blood flow when a person moves from lying or sitting to standing. It is characterized by an abnormally large increase in heart rate on standing, often accompanied by symptoms like dizziness, lightheadedness, and fatigue.

In POTS, blood may pool in the lower body when someone stands up, forcing the heart to beat faster in an attempt to maintain blood flow to the brain. This can cause a person to feel faint, unsteady, or as if their vision is dimming, especially after standing for several minutes. POTS is more common in younger people and those assigned female at birth, but it can affect anyone.

How POTS affects the body

When a healthy person stands, the body quickly tightens blood vessels and slightly increases heart rate to keep blood flowing upward against gravity, according to the American Heart Association. In POTS, this adjustment is impaired, so the heart rate rises much more than normal while blood pressure often stays the same or fluctuates instead of dropping dramatically. This abnormal response can make standing or even sitting upright feel exhausting or uncomfortable.

Because the autonomic nervous system is involved in many body functions, POTS can cause a wide range of symptoms beyond dizziness standing up. People may experience brain fog, nausea, tremor, palpitations, and exercise intolerance, making daily activities, school, or work harder to manage over time.

Common POTS symptoms to watch for

Typical POTS symptoms often cluster together rather than appearing in isolation. Common features include:

• Dizziness or lightheadedness after standing for a few minutes
• Noticeable heart racing or palpitations on standing
• Generalized fatigue or feeling "wiped out" after relatively small activities

In addition, many people with POTS report symptoms such as brain fog, difficulty concentrating, headaches, nausea, shortness of breath, chest discomfort, shakiness, or a sense of internal "adrenaline." Some notice that symptoms worsen with heat, prolonged standing, menstruation, or after viral illnesses, and improve when lying down.

How long does dizziness last with POTS?

With POTS, dizziness standing up often begins shortly after moving upright and may persist as long as a person remains in that position, especially if they are standing still. Symptoms frequently improve when the person sits or lies down, as gravity's effect on blood pooling is reduced.

Because symptoms can fluctuate from day to day, many people benefit from keeping a brief symptom diary. Noting when dizziness occurs, how long it lasts, what position they were in, and whether they experienced other POTS symptoms can help clinicians see patterns over time.

Low blood pressure and dizziness

Orthostatic, or postural, hypotension refers specifically to a significant drop in blood pressure when a person stands up. This fall in pressure can reduce blood flow to the brain, causing dizziness, blurred or tunnel vision, weakness, or fainting. Older adults, people taking blood pressure medications or diuretics, and those who are dehydrated are particularly vulnerable.

When low blood pressure is the main problem, the heart rate may rise somewhat to compensate, but not to the same degree typically seen in POTS. Measuring blood pressure and heart rate when lying down and again after standing can help distinguish between these patterns, though formal testing should be guided by a healthcare provider, as per Mayo Clinic.

Can POTS cause low blood pressure?

POTS is primarily defined by heart rate changes rather than a specific blood pressure pattern, but some individuals do experience low or fluctuating blood pressure along with their POTS symptoms. In these cases, both tachycardia and low blood pressure can contribute to dizziness standing up, making symptoms feel more intense.

Others may have normal or even slightly high blood pressure while still meeting criteria for POTS. This is why focusing solely on the term "low blood pressure" can sometimes be misleading and why professional evaluation is essential when symptoms are frequent, severe, or worsening.

Why do people feel dizzy when standing?

From a physiological perspective, standing pulls blood toward the legs and lower body. The body must quickly constrict blood vessels and adjust heart rate to keep enough blood flowing to the brain and vital organs. If this response is delayed, insufficient, or exaggerated in the wrong way, dizziness or lightheadedness can occur.

Simple triggers like suddenly standing after sitting for a long time, being in a hot shower, or not drinking enough fluids can cause brief dizziness in otherwise healthy individuals. When dizziness is persistent or accompanied by other POTS symptoms, low blood pressure, chest pain, or fainting, it becomes more concerning and warrants assessment.

Diagnosis and medical evaluation

When dizziness standing up is frequent or disabling, medical evaluation is important. Clinicians usually start with a detailed symptom history, physical examination, and measurements of heart rate and blood pressure lying, sitting, and standing. In suspected POTS, some people undergo a standing test or tilt table test to document how heart rate and blood pressure change over time.

Additional blood tests, heart rhythm monitoring, or imaging may be ordered to rule out other causes such as anemia, thyroid disorders, structural heart disease, or neurologic conditions. A diagnosis of POTS is made when characteristic heart rate changes and symptom patterns are present, other major causes have been excluded, and symptoms have persisted for a meaningful period (often several months).

Living with chronic orthostatic symptoms

For those who are ultimately diagnosed with POTS or chronic orthostatic hypotension, the impact on everyday life can be significant. Daily routines, work schedules, and exercise plans often need adjustment to account for variable energy levels and symptom flares. Planning breaks, using stools or chairs when tasks involve prolonged standing, and pacing activities are common strategies.

Emotional and mental health support is also important. Because POTS symptoms and dizziness standing up are often invisible to others, people may feel misunderstood or dismissed. Education, support groups, and a validating medical team can make a substantial difference in coping and long-term quality of life.

Frequently Asked Questions

1. Can someone have POTS without feeling dizzy?

Yes. While dizziness standing up is common in POTS, some people mainly notice extreme fatigue, brain fog, or a racing heart rather than obvious lightheadedness. They might not connect these symptoms to posture changes until a clinician measures heart rate and blood pressure in different positions.

2. Does drinking more water always help dizziness when standing?

Increased fluid intake can reduce dizziness for many people with orthostatic problems, but it is not a cure-all and may not be appropriate for everyone. Those with heart, kidney, or certain endocrine conditions need tailored advice, so any major change in fluid or salt intake should be discussed with a healthcare professional.

3. Can POTS or orthostatic dizziness appear suddenly after an illness?

Yes. Some individuals report that POTS-like symptoms begin or worsen after viral infections, surgery, or periods of prolonged bed rest. In these cases, the autonomic nervous system may have been disrupted or deconditioned, and symptoms can evolve over weeks to months rather than appearing all at once.

4. Is it safe to exercise if dizziness happens when standing?

Many people with POTS or orthostatic dizziness can exercise safely, but the type and intensity often need modification. Clinicians commonly recommend starting with recumbent or semi-reclined activities, then gradually progressing under medical guidance, rather than abruptly engaging in upright, high-intensity workouts that could worsen symptoms.