May also be called: Hypo-osmolality
Hyposmolality (hi-pos-mo-LAL-it-ee) is a condition where the levels of electrolytes, proteins, and nutrients in the blood are lower than normal.
Blood is made up of blood cells suspended in a yellowish fluid called plasma. Plasma is 90% water and contains nutrients, proteins, hormones, and waste products.
Normally, the levels of water and other substances in plasma stay in balance. If the amount of water becomes too high, or if the amount of other substances becomes too low, it can upset the balance and lead to hyposmolality. This can be caused by drinking too many fluids and overhydrating the body. It can also be caused by a condition called hyponatremia, which is a low level of sodium in the blood.
Mild cases of hyposmolality usually have no symptoms. Moderate cases can cause nausea and headaches. In severe cases, hyposmolality can cause seizures and coma and may be life threatening, but such cases are rare.
In many cases, the body will fix a case of hyposmolality by producing diluted urine (urine with more water) to get rid of excess water. If the body can't do that, hyposmolality can be serious, but if it's identified early, it can almost always be treated effectively.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
