Patient Preparation:No special preparation is required
A sodium test is usually ordered with other electrolytes like potassium, chloride and bicarbonates. A measurement of these electrolytes gives an indication of electrolyte balance that has implications in several diseases.
Your doctor may recommend this test for you if you show symptoms of either low or high sodium in your blood. These include:
Muscle cramps
Nausea
Frequent headaches
Swelling the body
Sodium is critical element, as it helps in maintaining blood pressure, as well as normal functioning of muscles and nerves. Sodium holds water in the blood and high levels increases the blood volume thereby increasing the pressure. The human body regulates sodium level extremely carefully to maintain optimum levels, especially the kidneys. The kidneys sense the sodium level in the blood and whenever high level is found, kidneys eliminate it. And in case of low sodium levels, it retains it be reabsorbing the sodium from the blood that is initially filtered by the kidneys.
A low level of sodium could be attributed to many reasons:
loss of sodium from the body
Increased intake of water
Edema (fluid accumulation in the body)
Hypernatremia or low sodium is most commonly attributed to conditions such as Addison's disease, diarrhoea or kidney disease. Heart failure and liver cirrhosis causes water retention which leads to low level of sodium in blood. Kidney diseases that cause protein losses also lead to Hypernatremia.
A high blood sodium level is mostly attributed to inadequate water intake and dehydration. Symptoms include dry mucous membranes, thirst, agitation, restlessness, acting irrationally, and coma or convulsions if the sodium level rises to extremely high concentrations. In rare cases, hypernatremia may be due to Cushing syndrome or a condition caused by too little ADH (Anti Diuretics) called diabetes insipidus.
Sample: Serum (2 mL)
Methodology: Indirect ISE