If stuck in a raft and run out of water, do not drink seawater. It is loaded with salt! We are only meant to ingest small amounts of salt, seawater contains deadly amounts to the human body (NOAA, 2014). Drinking seawater will cause you to die of dehydration your kidneys can only make urine that is less salty than water. So all the salt that is in seawater, you need to expel. You would have to urinate more out than what you drank. Thus, causing dehydration.
Kidney failure is when approximately 85-90% of kidney function is gone (NKF, 2022). When you have kidney failure your kidneys do not adequately work to keep you alive. Treatment is available but there is no cure. Healthy kidneys are used for important processes of the body such as removing waste products and extra water from your body, aid in making healthy red blood cells, and help maintain blood pressure (NKF, 2022). These are all crucial for maintaining homeostasis and the survival of living organisms. Homeostasis is a self-regulating process that regulates internal variables needed to sustain life (BYJUS, 2021). This allows the body to maintain a stable internal environment regardless of any external forces.
Kidneys are a type of filtering plant for the body. They separate toxins from the good stuff, nutrients, and get rid of the waste (Kane, 2022). When the kidneys, or kidney, is not functioning properly it causes this waste to back up in the body. This can lead to high blood pressure, heart failure, and neurological issues. Ultimately, kidney disruption can cause death. Many different diseases and disorders can cause kidney failure such as diabetes, high blood pressure, urinary reflux, glomerulonephritis (inflammation of the little filters), polycystic kidney disease, some medications and others. We have not had anyone in our family with kidney failure, however, several of us have kidney scarring due to chronic kidney stones and are followed by nephrology. This is more than likely hereditary as my father (74 yoa), myself, and both of our daughters (ages 23 and 17) all suffer from multiple stones and kidney infections a year. We had a neighbor once that we helped when she would fall ill. She had just turned forty but had a kidney transplant eight years prior. She was going to dialysis four times a week and was on the list for another transplant as the kidney was also failing. It is not an easy thing to watch someone devote hours every day, several days a week to dialysis just to live. She wasn’t able to drink like she wanted too and lived on ice chips for hydration.
When you drink water from the sea, your body will need more water to get rid of the high level of salt present in the water. Therefore, if you keep drinking seawater, you’ll keep adding to the amount of salt you need to get out of your body. Our body observes water through the process of osmosis. Osmosis is a process by which the molecules of a solvent pass from a solution of low concentration to a solution of high concentration through a semi-permeable membrane (Bozeman 2021).
In our bodies, we have cell members which allow water to pass through but not particle dissolves in water. The salt inside and outside our cells remains in equilibrium. When we drink water, water from the outside of our cell moves inside of our cell to remain at an isotonic state. If you drink too much seawater the salinity outside your cells will increase rapidly. This forces too many water molecules to move out of your cells so even if you’re already dehydrated, your cells will release water rather than absorb it. Thus, drinking seawater is not only a bad idea but potentially fatal.
A healthy kidney maintains homeostasis through the removal of harmful wastes from the body and controls the balance of substances in the blood such as water, acids, ions, and salts. The kidneys and homeostasis are vital for internal health and function. Kidneys act as a natural filter for all the waste products produced in the body, they also help to regulate the fluid and electrolyte balance (BD Editors, 2018). They help to keep the blood pressure within normal limits and secrete a hormone that helps in red blood cell production. When kidneys fail to perform their normal function, the waste products accumulate in the blood and the fluid balance is disturbed, this is termed as kidney failure on ESRD (End-Stage Renal Disease), which can happen gradually or suddenly(New Health Advisor, 2019). People with ESRD need dialysis or transplant to sustain life.