What should you know about POTS and postural hypotension?

The two conditions can overlap in how they feel, but they are assessed differently. A clinician may ask what happens when you move from lying or sitting to standing, check your pulse and blood pressure, and review medicines or illnesses that could contribute.

When you stand, gravity draws some blood towards your legs. The body normally tightens blood vessels and adjusts the heart rate to keep blood flowing to the brain. With postural hypotension, that response is not sufficient, so you may feel light-headed, unsteady, weak, blurred in your vision, or briefly lose consciousness.

Symptoms may be more noticeable after lying down for a while, in hot weather, after a large meal, during dehydration, or when standing still. Possible contributors include fluid loss, anaemia, nervous-system problems, heart conditions, and medicines that lower blood pressure. Do not stop a prescribed medicine without medical advice.

POTS, short for postural orthostatic tachycardia syndrome, is defined by symptoms that worsen upright together with an exaggerated heart-rate response. Blood pressure may remain fairly stable, although some people with POTS can also experience a blood-pressure drop. Testing is needed to tell these patterns apart.

Rise in stages: sit on the edge of the bed, move your ankles and legs, then stand slowly while holding a stable surface. If symptoms begin, sit or lie down promptly and raise your legs if comfortable. Avoid driving, climbing, or using machinery while you feel faint.

Regular fluids, gentle movement, and avoiding prolonged standing or excessive heat may help some people. Your clinician may suggest compression garments, changes to a medicine, or a supervised plan for salt and fluid intake; these options are not suitable for everyone, particularly people with heart or kidney disease.

Keep a brief record of triggers, symptoms, meals, fluids, medicines, and whether your pulse feels unusually fast. This can help a GP assessment focus on the pattern rather than a single episode.

Arrange a GP consultation if dizziness or near-fainting keeps happening, begins after a medicine change, limits normal activities, or is accompanied by a racing heartbeat. A first faint, repeated falls, or symptoms during exercise also deserves prompt assessment.

Seek emergency help for fainting with chest pain, severe breathlessness, a new irregular heartbeat, sudden weakness, trouble speaking, a severe headache, significant injury, or prolonged confusion. Get urgent help if someone remains unconscious or does not recover normally.

Ask whether your symptoms fit postural hypotension, POTS, or another cause; whether your medicines, hydration, blood count, heart rhythm, or nervous system need checking; and which fluid, salt, exercise, or compression advice is safe for you.