Lifestyle

6 Signs of Low Blood Sodium Most People Mistake for Normal Aging

By Mike Harper · October 20, 2026

After years of being told to cut back on salt, it can be hard to believe that too little sodium in the blood is a real problem. It is, and it is more likely as we age. The Mayo Clinic says older adults may have more contributing factors for low blood sodium, called hyponatremia, including age-related changes, certain medicines, and a greater chance of chronic disease.

Sodium helps control the water in and around your cells and supports your nerves and muscles. A healthy blood level is between 135 and 145, and anything below 135 counts as low, according to the National Kidney Foundation. In most cases the issue isn’t too little salt in your diet. NKF says it is more often about too much water in the body, which dilutes the sodium.

Common culprits include water pills such as hydrochlorothiazide and chlorthalidone, some antidepressants, seizure medicines, heart failure, kidney disease, and liver disease. Cleveland Clinic adds low thyroid and heavy beer drinking to the list. Severe vomiting or diarrhea can also do it.

When sodium drops slowly, the symptoms can be subtle. These six are easy to write off as age.

Feeling unsteady on your feet. In a study published in The American Journal of Medicine, 21.3% of patients with mild, long-standing low sodium were admitted to the emergency department for falls, compared with 5.3% of similar patients without it. Their average age was 72, and their low sodium had been considered symptom-free. Testing showed shakier walking and slower attention, changes the researchers compared to the effects of drinking alcohol.

Fuzzy thinking. Mayo and Cleveland Clinic both list confusion. Cleveland Clinic says chronic low sodium can bring slow-building symptoms like difficulty thinking, and suggests talking with your provider about even small changes in how you feel.

Running out of energy. Mayo lists loss of energy, drowsiness, and fatigue. NKF lists low energy or fatigue.

Muscle cramps or weakness. Mayo, MedlinePlus, and NKF all include muscle weakness, spasms, or cramps.

Headache, nausea, or a poor appetite. MedlinePlus, the National Library of Medicine’s health site, lists headache, nausea, vomiting, and loss of appetite.

Dizziness when you stand up. NKF lists dizziness on standing and low blood pressure, along with restlessness or a short temper.

NKF notes that most people with mild low sodium have no symptoms at all. That is one reason to know your number. Sodium is part of the basic and comprehensive metabolic panels, MedlinePlus says, so it may already be on your last blood test report. If you take a water pill or an antidepressant, ask your doctor whether your sodium is being checked.

Don’t try to fix it yourself. NKF says treatment depends on the cause and should be supervised by a professional, and Cleveland Clinic warns that raising sodium too quickly can cause serious brain damage. Treatment might mean limiting fluids, changing a medicine, or treating the underlying condition. A level just under 135 may only need a recheck, according to NKF.

Some situations are emergencies. Cleveland Clinic says to go to the emergency room for confusion, seizures, difficulty waking up, a severe headache, or severe vomiting or diarrhea. MedlinePlus says a fast drop is more dangerous than one that develops slowly, and Mayo says a rapid fall can cause dangerous brain swelling.

This article is for general information and is not medical advice. Do not stop or change any medicine without talking to your doctor. If someone has confusion, a seizure, or trouble waking, call 911.