Blood pressure below 90/60 mmHg is considered low, and a wide range of everyday factors can push it there. Some people naturally run on the lower end and feel perfectly fine. Others notice dizziness, fatigue, or lightheadedness that signals something worth investigating. The cause could be as simple as not drinking enough water or as specific as a medication side effect.
What Counts as Low Blood Pressure
Normal blood pressure for most adults falls below 120/80 mmHg. Low blood pressure, or hypotension, starts at readings below 90/60 mmHg. That said, the number alone doesn’t tell the whole story. If your blood pressure has always hovered around 95/60 and you feel fine, that’s likely just your normal. Low blood pressure only becomes a medical concern when it causes symptoms or drops suddenly from your usual baseline.
The most common symptoms include dizziness, lightheadedness, blurred vision, nausea, fatigue, and feeling like you might faint. If you’re checking your blood pressure at home and getting low readings but feeling completely normal, there’s usually no reason to worry.
Dehydration Is the Most Common Culprit
Your blood is mostly water. When you’re not drinking enough, or you’re losing fluid through sweating, vomiting, diarrhea, or fever, your blood volume drops. Less blood in the system means less pressure pushing against your artery walls. Think of it like a garden hose that’s only halfway full: the water trickles out instead of spraying. When blood volume gets low enough, your organs may not receive the oxygen they need to work properly.
This is one of the easiest causes to fix. Increasing your fluid intake, especially during hot weather, exercise, or illness, can bring your pressure back up within hours. If you’re prone to low readings, keeping a water bottle nearby throughout the day makes a noticeable difference.
Medications That Lower Blood Pressure
Many common medications can drop your blood pressure as a side effect, sometimes intentionally, sometimes not. If your low readings started around the same time you began a new medication, that’s a strong clue.
The biggest offenders include:
- Blood pressure medications: Diuretics (water pills), calcium channel blockers, beta blockers, and ACE inhibitors are all designed to lower pressure, and sometimes they overshoot.
- Antidepressants: Tricyclic antidepressants and SNRIs commonly cause blood pressure drops, especially when standing up. SSRIs do this less often but can in some people.
- Alpha blockers: Often prescribed for prostate problems, these frequently cause significant drops in blood pressure.
- Heart medications: Nitroglycerin and similar drugs can cause sudden, steep drops in pressure.
- Parkinson’s disease medications: Dopamine-related drugs used for Parkinson’s are known to cause low blood pressure as a side effect.
If you suspect a medication is the cause, don’t stop taking it on your own. Your prescriber can adjust the dose or switch you to an alternative.
Standing Up Too Fast
If your blood pressure drops specifically when you go from sitting or lying down to standing, that’s called orthostatic hypotension. You know the feeling: you stand up and the room briefly swims, your vision darkens at the edges, or you feel like you need to grab something for balance. It happens because gravity pulls blood into your legs and your body doesn’t compensate quickly enough.
Common triggers include dehydration, prolonged bed rest, certain medications (especially diuretics and antidepressants), and conditions that affect the nervous system like diabetes and Parkinson’s disease. Aging also plays a role, since the reflexes that adjust blood pressure slow down over time. Standing up slowly, pausing at the edge of the bed before getting to your feet, can reduce these episodes significantly.
Eating a Large Meal
Some people experience blood pressure drops after eating, particularly after large, carbohydrate-heavy meals. Your body redirects a significant amount of blood flow to your digestive system after a meal, and in some people the heart and blood vessels don’t fully compensate. This is more common in older adults and people with conditions affecting the nervous system. Eating smaller, more frequent meals and limiting refined carbohydrates can help.
Nutritional Deficiencies
Low levels of vitamin B12 or folate can lead to a type of anemia where your body produces red blood cells that are too large and don’t carry oxygen efficiently. When your tissues aren’t getting enough oxygen, you may feel dizzy, fatigued, and weak, symptoms that overlap heavily with low blood pressure. Iron deficiency works through a similar pathway. If your low blood pressure is accompanied by persistent fatigue and pale skin, a simple blood test can check for these deficiencies.
Pregnancy
Blood pressure naturally drops during pregnancy, and it starts earlier than most people expect. The decrease begins around 6 to 8 weeks of gestation as blood vessels relax and widen to support increased blood flow to the uterus. Pressure typically reaches its lowest point in the middle of the second trimester, falling 5 to 10 mmHg below pre-pregnancy levels, before gradually climbing back toward baseline in the third trimester.
Mild dizziness during early and mid-pregnancy is common and usually harmless. Staying hydrated and avoiding standing for long periods helps. A sudden or severe drop, especially with heavy bleeding or severe abdominal pain, is a different situation that needs immediate attention.
Heart and Endocrine Conditions
Less commonly, persistently low blood pressure points to an underlying condition. Heart problems like an extremely slow heart rate, heart valve disorders, or heart failure can reduce the amount of blood your heart pumps with each beat. Endocrine issues, particularly an underactive thyroid or adrenal insufficiency (where your adrenal glands don’t produce enough hormones), can also lower blood pressure. These conditions usually come with other noticeable symptoms: unexplained weight changes, chronic fatigue that rest doesn’t fix, or swelling in the legs.
Severe infections that spread to the bloodstream can cause a dangerous and rapid drop in blood pressure. This is a medical emergency and comes with obvious signs of serious illness like high fever, confusion, rapid breathing, and cold or clammy skin.
Simple Ways to Raise Low Blood Pressure
If your low blood pressure causes symptoms but doesn’t stem from a serious medical condition, several lifestyle changes can help. Drinking more water is the single most effective step. Adding a bit more salt to your diet can also raise blood pressure slightly, though most adults already consume well above the recommended 2,300 mg of sodium per day. If your doctor has specifically suggested increasing salt intake, aim for that guidance rather than adding it indiscriminately.
Compression stockings, the kind that squeeze your calves and thighs, reduce the amount of blood that pools in your legs and can prevent the drops that happen when you stand. Eating smaller meals more frequently keeps blood from rushing to your digestive system all at once. Crossing your legs while sitting or tensing your thigh muscles before standing are small tricks that help push blood back toward your heart.
Caffeine offers a short-term boost, and some people find that a cup of coffee before activities that trigger dizziness helps them get through. The effect is temporary and diminishes if you drink caffeine regularly, but it can be a useful tool on days when symptoms are worse.