Table salt is not only a commonly used seasoning, but also contains sodium, a nutrient needed by the human body. Sodium helps muscles and nerves work properly and ensures that the body retains the proper amount of fluids. Too much sodium is bad for the body, however, and can even lead to hypernatraemia, or salt poisoning. Symptoms of salt poisoning include excessive thirst, change in mental state and muscle twitching or stiffness.

Salt poisoning can have a number of causes. Typically, an individual's sodium intake alone will not be sufficient to cause hypernatraemia, although patients who receive large doses of solutions such as sodium bicarbonate may be at risk. More often, the condition arises when people either do not consume enough water or lose excessive amounts of fluids due to conditions including diabetes, severe burns or even excessive vomiting and diarrhea.

Increased thirst may be an initial symptom of salt poisoning. Thirst is triggered by the increase in sodium levels in the body. Many patients may only experience excessive thirst for a short time or not at all. Patients who are already suffering from an altered mental state are less likely to exhibit this symptom.

Changes in mental state may also indicate hypernatraemia. If salt poisoning comes on very quickly, an onset referred to as acute, or is very severe, the lack of fluids in the body can affect the brain. In these cases the brain can actually shrink, often causing enough tension on blood vessels in the organ to make the vessels rupture and leak blood. These physical changes may cause the patient to become irritable, delirious or even lapse into a coma.

If the muscles are deprived of fluids due to salt poisoning, they may also undergo changes such as shrinkage. This may cause the muscles to twitch uncontrollably, resulting in a visible tremor. Patients suffering from hypernatraemia may also find their muscles becoming very rigid, leading to an inability to move their limbs properly.

Treatment options for salt poisoning may vary by patient. Typically, the patient will receive intravenous fluids and water by mouth to restore the proper balance of sodium and fluids in the body. This treatment is usually completed within 48 hours, but it is vital that the patient does not receive the fluids too rapidly or slowly. The attending physician must carefully evaluate the cause, duration and speed of onset to determine the correct time frame for completion of treatment. Diabetic patients may also require treatment with anti-inflammatory medications and hormones.