What is hyponatremia? — Hyponatremia is the medical term for "too little sodium." In people with this condition, the body holds on to too much water. That dilutes the amount of sodium in their blood.

Sodium is one of many substances called "electrolytes" that help carry electrical signals between cells. That's important because many cells rely on electrical signals to work right. Sodium also helps keep the right amount of fluid inside cells.

Symptoms of hyponatremia include:

●Nausea and vomiting

●Headache

●Confusion or trouble thinking clearly

●Feeling weak or tired

●Feeling restless or irritable

●Muscle weakness, spasms or cramps

●Seizures or passing out

Hyponatremia can also cause more serious problems, such as brain swelling and nerve damage.

What causes hyponatremia? — Hyponatremia happens when the body holds onto too much water. This can happen because of:

●Certain medical conditions that cause your body to hold onto too much water. These include:

•Heart failure, a type of heart disease in which the heart cannot pump as well as it should

•Cirrhosis, a severe form of liver disease

•Kidney disease

•Lung disease

●Some medicines, including a diuretic called hydrochlorothiazide (HCTZ), which makes you urinate a lot

●Drinking too much water. This can happen to:

•Athletes who do intense exercise (such as run marathons) and drink too much water

•People who use the drug ecstasy (ecstasy can make you feel thirsty and drink too much)

•People who are mentally ill and feel as though they cannot get enough to drink

●Blood loss (for example, after an injury)

●Long-lasting, severe vomiting or diarrhea (this causes your body to lose fluids and sodium)

●Poor diet

Are there tests I should have? — You will need blood and urine tests to get diagnosed with hyponatremia. You might also need other tests depending on your age, other symptoms, and individual situation.

How is hyponatremia treated? — That depends on what is causing your hyponatremia. If your hyponatremia is caused by another medical problem, such as heart failure, your doctor or nurse will want to treat that, too.

Treatments might include:

●Limiting the amount of fluid you drink

●Eating salt tablets or getting a salt-water solution into a vein