You can raise low blood pressure by drinking water and eating more salt.
Low blood pressure, or hypotension, is considered lower than 90/60 mm Hg.
If another health condition is causing low blood pressure, you may need to take medication or wear compression stockings to raise it.

A blood pressure reading lower than 90 mm Hg systolic (the top number) or 60 mm Hg diastolic (the bottom number) is generally considered low blood pressure, or hypotension.

Here's what you need to know about hypotension, when it's considered dangerous, and the best ways to raise low blood pressure.
How to raise low blood pressure

The occasional low blood pressure reading is not cause for concern, especially if it comes with no other symptoms. However, if low blood pressure is persistent and symptoms are present, your doctor may recommend measures to raise it.

"We try to raise blood pressure when people have symptoms such as dizziness and fainting," says Sonia Tolani, MD, a cardiologist and assistant professor of medicine at Columbia University Medical Center.

Tolani says the two most common ways to raise blood pressure are:

Eat more salt: Generally, the higher your sodium intake, the higher your blood pressure. Long-term, this can put an extra burden on your heart and blood vessels, so you should consult your doctor before adding too much sodium to your diet, as it may increase the chances of other cardiovascular conditions.
Stay hydrated: Make sure you are drinking water because fluids increase blood volume and help prevent dehydration. Tolani says both drinking water and increasing sodium is best and tells patients with low blood pressure to have a salty snack - like salted nuts or a pickle - between meals with a big glass of water.

For the most part, these lifestyle modifications can help raise your blood pressure. But if related health conditions or prescription medication are causing the low blood pressure, you may need to take other measures.

Pre-existing health conditions require different methods

Tolani says people with Parkinson's are prone to have rapid swings in blood pressure, which can result in very low readings. Neurogenic orthostatic hypertension is common in Parkinson's disease, with about 40% to 60% of people experiencing low blood pressure readings.

Orthostatic hypotension is a condition that causes low blood pressure within three minutes of standing up, and doctors may prescribe medication to help manage it. However, some drugs for Parkinson's are also known to decrease blood pressure, so you should talk to your doctor about the right medication for both.

Diuretics and beta-blockers, which are often prescribed for high blood pressure, can also lower your blood pressure by too much. If medication is the cause of your low blood pressure, your doctor may recommend adjusting the dose or changing the medication.

Finally, if you have sepsis shock, low blood pressure urgently needs to be raised. Glenn Keyes, MD, a family physician at Copeman Healthcare Centre in Edmonton, says "this is done with fluids, and sometimes special medications (pressors) are used through an IV."
Do compression socks raise low blood pressure?

One lifestyle measure often recommended to raise blood pressure are compression socks, which are stockings that put gentle pressure on your legs to move blood up to the heart.

"Compression socks increase the blood return to the heart, which helps to raise the overall blood pressure," says Keyes. This is critical for anyone who is experiencing blood pooling in the legs, which frequently occurs with orthostatic hypotension.

However, Keyes says it's important to talk to your doctor before wearing compression stockings, since they may not be recommended in the presence of other health conditions, such as certain forms of heart failure and peripheral vascular disease.