When your blood pressure drops, the most important immediate step is to lie down or sit with your head between your knees. Low blood pressure, defined as a reading below 90/60 mmHg, can cause dizziness, lightheadedness, blurred vision, and fainting. What you do next depends on whether this is a one-time episode or a recurring pattern.
What to Do Right Now
If you feel dizzy or faint, lie down immediately. If lying down isn’t possible, sit and place your head between your knees. Don’t stand back up quickly once you feel better, as that can trigger a second drop.
If someone near you faints from a blood pressure drop, position them on their back and raise their legs about 12 inches above heart level. Loosen any tight clothing around their neck, chest, or waist. Keep them lying down until they feel fully recovered, then help them sit up slowly before standing.
While you’re resting, drink water. Research published in the American Heart Association’s journal Circulation found that drinking about 16 ounces (480 mL) of water raises systolic blood pressure within 5 minutes, peaks around 30 to 35 minutes later, and sustains the effect for over an hour. In older adults, the increase averaged 11 mmHg. Even half that amount of water helps, though the larger volume produces a stronger response. This is one of the simplest tools you have.
When a Blood Pressure Drop Is an Emergency
A brief dip that causes mild dizziness is common and usually not dangerous. But certain symptoms signal that blood pressure has dropped to a level where your organs aren’t getting enough blood. Call emergency services if you or someone else experiences:
- Confusion or difficulty thinking clearly
- Cold, clammy, or pale skin
- Rapid, shallow breathing
- A weak, rapid pulse
- Loss of consciousness that doesn’t resolve quickly
These can indicate shock, which is a medical emergency. Don’t try to manage it at home with fluids or rest.
Common Reasons Blood Pressure Drops
Understanding why your blood pressure is dropping helps you prevent it from happening again. The most frequent triggers fall into a few categories.
Positional Changes
Standing up too quickly is the most common cause of sudden blood pressure drops. When you rise, gravity pulls blood into your legs. Normally your body compensates within seconds, but if that reflex is sluggish, your brain briefly loses adequate blood flow. This is called orthostatic hypotension, and it’s especially common in older adults, people who are dehydrated, and those on certain medications.
Eating Large Meals
Blood pressure can drop after eating because your body redirects blood flow to your digestive system. This is called postprandial hypotension, and it tends to hit within 30 to 75 minutes after a meal. Large, carbohydrate-heavy meals are the biggest trigger.
Dehydration and Heat
Your blood volume directly affects your blood pressure. When you lose fluids through sweating, illness, or simply not drinking enough, there’s less fluid in your blood vessels and pressure falls. Hot environments make this worse by dilating blood vessels at the same time you’re sweating out fluid.
Medications
Many common medications lower blood pressure as either their intended effect or a side effect. Blood pressure and heart medications are obvious culprits, including diuretics (water pills), beta blockers, calcium channel blockers, and nitrate drugs used for chest pain. Nitrate medications in particular are a common cause of sudden fainting from rapid blood pressure drops.
Less obvious are medications that act on the brain. Older antidepressants (tricyclics) and drugs used for psychosis commonly cause blood pressure to drop when standing. Some newer antidepressants in the SNRI class do this too. Medications for Parkinson’s disease, including dopamine-based drugs, are also frequent offenders. If you’ve recently started a new medication or changed doses and notice more dizziness, the timing is probably not a coincidence.
Dietary Changes That Help
If low blood pressure is a recurring issue for you, daily habits can make a meaningful difference.
Increase your fluid intake throughout the day, not just when you feel symptomatic. Keeping a water bottle with you and sipping consistently is more effective than drinking large amounts all at once. The blood pressure boost from water is real and measurable, but it fades after about an hour, so steady intake matters.
Salt is the other side of the equation. While most health advice warns against excess sodium, people with orthostatic disorders are routinely advised to consume more than 2,300 mg of sodium per day to help maintain blood volume. This is a case where general dietary guidelines don’t apply. Adding salt to meals or eating salty snacks can help, but talk to your provider about the right target for your situation, especially if you have kidney or heart issues.
If your blood pressure tends to drop after eating, switch to six smaller meals throughout the day instead of three large ones. Keep those meals low in carbohydrates, since carbs trigger more blood flow to the gut and a larger pressure drop. A lunch of grilled chicken and vegetables will affect your blood pressure far less than a plate of pasta.
Daily Habits to Prevent Drops
Beyond diet, a few physical strategies reduce the frequency and severity of episodes.
Get up slowly. This sounds simple, but it’s the single most effective prevention for positional drops. When you wake up in the morning, sit on the edge of the bed for 30 seconds before standing. When you rise from a chair, pause before walking. Give your cardiovascular system time to adjust.
Compression stockings help keep blood from pooling in your legs. They’re particularly useful if you stand for long periods or have been told you have venous pooling. Waist-high versions work better than knee-high ones because they cover more vascular territory.
Crossing your legs and tensing your thigh muscles while standing can provide a quick blood pressure boost when you feel a drop coming on. Squeezing a rubber ball or making tight fists works similarly by activating muscles that push blood back toward your heart. These physical counter-maneuvers buy you time in the moment.
Avoid alcohol, which dilates blood vessels and worsens hypotension. Hot baths and saunas have the same vasodilating effect and can trigger dramatic drops, especially if you stand up quickly afterward. If you enjoy hot showers, keep them shorter and sit down if you feel lightheaded.
Ongoing Low Blood Pressure
Some people simply run low and feel fine. A blood pressure of 85/55 in someone with no symptoms isn’t a medical problem. Low blood pressure only needs treatment when it causes symptoms like dizziness, fainting, fatigue, or difficulty concentrating.
If you’re experiencing frequent drops despite hydration, salt, and lifestyle changes, it’s worth investigating underlying causes. Conditions that affect the nervous system, including diabetes-related nerve damage, Parkinson’s disease, and some autoimmune conditions, can impair the reflexes that regulate blood pressure. Hormonal conditions affecting the adrenal glands can also be responsible. Blood work and a tilt-table test, where your blood pressure is monitored while you’re gradually tilted upright, can help identify what’s going on.
If medications are contributing, your provider may adjust the dose, switch to a different drug, or change the timing so you take blood pressure-lowering medications at bedtime instead of in the morning when you’re most active and vulnerable to drops.