Symptoms
Low blood pressure: what to do when your pressure drops
Is this an emergency?
This is not an emergency service. Call 911 or go to the nearest emergency room if you have:
- Fainting or losing consciousness
- Chest pain, shortness of breath or an irregular heartbeat
- Confusion
- Black or bloody stools, or vomiting blood
- Cold, sweaty skin, fast breathing or a weak, rapid pulse
Help lines
Low blood pressure (hypotension) is a reading below 90/60 mm Hg. Many people have it with no symptoms, but when your pressure drops you may feel dizzy, have blurry vision or nausea, or faint. If that happens, sit or lie down and raise your feet. Common causes are dehydration, heat and some medicines. If you faint or have chest pain, call 911.
Other names: Hypotension, Low BP
Possible causes
Dehydration or heat
Vomiting, diarrhea, heavy sweating or not drinking enough
Blood pressure medicines and diuretics
More common in older adults; the doctor checks whether to adjust them
Standing up quickly (orthostatic hypotension)
Dizziness when getting out of bed or a chair
Blood loss or anemia
Black stools can mean bleeding: that is an emergency
Pregnancy
Pregnancy can lower blood pressure
Heart or heart-rhythm problems
With chest pain, shortness of breath or palpitations, it is an emergency
On this page(6)
What is low blood pressure?
According to the NIH, normal blood pressure for most adults is under 120/80 mm Hg, and low blood pressure is under 90/60 mm Hg. Many people run low and feel fine; it matters when it causes symptoms, because then the brain, heart and other organs may not be getting enough blood.
There are several types. Orthostatic hypotension drops when you stand up after sitting or lying down. Postprandial hypotension drops after eating and is more common in older adults. Neurally mediated hypotension happens more in young people and children who stand for a long time. And very low pressure from shock is an emergency.
How we help by video when your pressure drops
You see Dr. Diana Nieves Castro, a Puerto Rico-licensed general practice physician with several years of emergency-department experience, in English or Spanish. If you have a home blood pressure monitor, have your readings ready. The doctor asks when it happens, how much you drink, whether you have had vomiting, diarrhea or a lot of heat, and goes over all your medicines with you.
We evaluate, diagnose and treat. If you take pills for high blood pressure or diuretics, the doctor checks whether they need adjusting; don’t stop them on your own. If needed, we give you a lab order for a lab near you, for example a blood count to look for anemia. If appropriate, the doctor prescribes and we send your prescription to your pharmacy.
A doctor visit costs US$79, the same price for every age, with no membership. Request a visit online 24/7 — we confirm your time by email or text.
Your doctor
Dr. Diana Nieves Castro, MD
General practice physician
Several years of emergency-department experience.
Founding Executive Director of The Health Initiative.
Low blood pressure symptoms
According to the NIH and MedlinePlus, when low blood pressure causes symptoms you may have:
- Dizziness or feeling about to faint
- Fainting
- Blurry vision
- Nausea
- Weakness or tiredness
- Headache
- Heart palpitations
What to do when your blood pressure drops
MedlinePlus advises you to sit or lie down right away and raise your feet above the level of your heart. Stay there until the dizziness passes, then get up slowly.
To keep it from happening again: drink enough fluids, especially in Puerto Rico’s heat; get up slowly from bed or a chair; avoid alcohol; and, if your doctor recommends them, wear compression stockings when you will be standing for a long time. If the dizzy spells keep coming back, see also dizziness and dehydration.
When low blood pressure is an emergency
For your safety, call 911 or go to the emergency room if low blood pressure comes with any of these signs. See when to go to the ER.
- You fainted or lost consciousness
- Chest pain, shortness of breath or an irregular heartbeat
- Confusion
- Black or bloody stools, or vomiting blood
- Cold, sweaty skin, fast breathing, bluish skin or a weak, rapid pulse (signs of shock)
Frequently asked questions
What should I do if my blood pressure drops?
What counts as low blood pressure?
Can blood pressure pills make my pressure too low?
Can heat lower my blood pressure?
About this page
Author: The Health Initiative
Medical care provided by Dr. Diana Nieves Castro, MD (PR license 24027)
Disclosure: Founding Executive Director of The Health Initiative
Published: 2026-10-02 · Updated: 2026-10-02
Sources (3)
- Low Blood Pressure (NHLBI, NIH) (opens in a new tab) (accessed 2026-10-02)
- Low blood pressure (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)
- Stools - black or tarry (MedlinePlus, NIH) (opens in a new tab) (accessed 2026-10-02)