The sensation of thirst is one that all humans experience, and it’s a natural neurological signal from the body that we need to take in more fluids. But, when our thirst becomes excessive or prolonged, what is our body trying to tell us?
The basics of thirst
In the brain, a small collection of cells named the lamina terminalis can detect the levels of both fluid and sodium in the body at any given moment, and if fluid levels are deemed low, the drive to drink is initiated through the sensation of thirst. The lamina also processes information sent from other parts of the brain regarding blood pressure, blood volume and other important aspects of homeostasis.
The balance of sodium and other electrolytes is key to many bodily functions, and when fluid levels are too low or high, electrolyte levels are impacted by relative dilution or concentration and can trigger all manner of physiological responses, some of which can be problematic or even life-threatening.
Thirst is triggered under many conditions, and the drive to replace lost fluids keeps our bodies functioning optimally. So, when thirst is excessive (polydipsia), something is amiss.
Causes of excessive thirst
Excessive or constant thirst are signals that we need to pay close attention to. Some potential causes of these symptoms are:
- Diabetes mellitus
- Spicy foods
- Vomiting and diarrhea
- Significant blood loss
- Poor fluid intake due to various causes such as dementia, or certain mental illnesses
- Heart, liver or kidney failure
- Cushing’s syndrome
- Sjogren’s syndrome
- Kidney failure
- Diabetes insipidus
In diabetes, excess sugar…