Thyroid Function and Kidneys and Electrolytes

People are aware of the symptoms of low sodium. Migraines, confusion, fatigue, nausea, vomiting, muscle cramps, muscle spasms, and weakness are common symptoms. It’s normal to need salt after intense sports. It’s not only because you will probably sweat. When you sweat, you lose water, and sodium goes out. You will need more salt, and your activity will be more intense. The adrenals need salt since intense activity will activate the fight-or-flight nervous system. The adrenals will then excrete stress hormones.But what if you feel like that all the time? Even though you take electrolyte supplements in powder form or capsules, drink water and salt you left out in the sun. You’d think you have enough potassium, sodium, and chloride. However, your electrolytes will be out of balance if you have low thyroid function and a low T3 level. Then, if you add more potassium when you have cramps, you will lower your sodium level. Then you will have symptoms of low salt. Then you stop salting your food because your ankles swell, or you notice that the slightest amount of salt makes them swell even more. Then you start to feel worse because you are lowering your aldosterone level. Aldosterone is a hormone produced by the adrenal glands that regulate fluid levels in the body. With a low aldosterone level, you will feel even more dizzy and tired.

Low thyroid function causes multiple changes in kidney function. Remember, with low thyroid function, every physiological process in the body slows down. There will be a direct alteration in renal reabsorption, renal blood flow, cardiovascular function, and changes in mineral homeostasis.

Mineral levels get chaotic. I have already discussed how much cardiovascular function is affected by altered thyroid function. The heart beats slower, so it has to beat harder, and this causes hypertension. Low thyroid levels cause decreased peripheral oxygen, meaning organs and tissues get less. As a result, renal blood flow and glomerular filtration are reduced. The glomerular filtration rate test is a routine test everyone gets as part of their “preventative medicine” package. Yet, if the rate is decreased, few doctors think about checking thyroid function. Instead, they will probably tell you to eat less protein because of the myth that protein hurts the kidneys.

These are the significant changes in kidney function with a low thyroid hormone level. In the kidneys, nitric oxide regulates vascular tone and sodium excretion. Nitric oxide tells the kidneys to let go or to hold onto sodium. Hypothyroidism reduces levels of nitric oxide. Hence, less sodium is reabsorbed from the kidneys, which causes hyponatremia or low salt in your blood. Hyponatremia causes diminished cognitive function, headache, nausea, and poor balance. That’s why it’s associated with fractures in older people. As does low aldosterone, by the way. Low aldosterone causes the same symptoms as hyponatremia. There will be less sodium and potassium pump activity in the kidneys since although they reabsorb less salt, the kidneys will excrete more sodium but much less potassium. The Sodium potassium pumps are essential for all cell processes. They pump salt out of cells and potassium into cells. Sodium potassium pumps are the only way water and nutrients get into cells. Sodium potassium pumps also maintain the acidbase balance in our bodies and give our central nervous system its electrical charge. It’s how our neurons send signals. Reduced cellular sodium-potassium pumping causes swelling in all cells— in the ankles and the fingers. Dowager hump at the base of your neck? Swelling over the sacrum? Reduced kidney function due to low thyroid hormone levels can cause tissue swelling. Another change in renal function is that cells won’t respond to arginine vasopressin. Less water comes out of cells, and the kidneys concentrate less urine. So more swelling.

Parathyroid hormone regulates how the kidneys handle calcium, phosphorous, sodium, potassium, and magnesium. With low T3, the parathyroid hormone can signal the kidneys, but the kidneys cannot hear.

In physiology, it’s all about balance. Tired of being yelled at, those kidneys can release too much calcium and hold onto too much phosphate, leading to inactivated vitamin D. Yes, this will cause low vitamin D levels. There is less bone turnover in hypothyroidism. The parathyroid glands will have to work harder to maintain calcium levels. Consequently, there may be low renin and low angiotensin, which can cause dizziness and fatigue because angiotensin responds to stress, thus creating further adrenal issues.

Low thyroid also decreases levels of natriuretic peptide. Natriuretic peptide is what tells the kidneys to excrete sodium. With low natriuretic peptide, you will have too much sodium in cells and tissues, but it doesn’t get to the organs that need it. In this case, you will have all of the symptoms of low sodium —migraines, confusion, fatigue, nausea, vomiting, muscle cramps, muscle spasms, and weakness, but a tiny bit of salt on your food will make your ankles swell.

There will be increased capillary permeability and low lymphatic flow, which also means more swelling. Still, it also means that no garbage gets taken out and reduced removal of toxins from lymph, as well as the awful accumulation of glycosaminoglycans. All that swelling can become lumpy. Low salt causes water retention. Even if you give up all the carbs, you won’t pee out as much because the kidneys can’t absorb water from your tissues. This can cause non-pitting edema and swelling in the hands, feet, and eyelids. Fluid can collect in heart and lung tissue. Remember the glycosaminoglycans from the skin video? Here they are again, pulling up to 1000 times their weight in water from all that unfiltered water in all swollen cells, making a thick gelatinous mess in all the interstitial space in your body.

Since the kidneys don’t filter well, you will probably have high creatinine levels on your tests. Did you think you were overeating meat? Why no, the level is due to a reduced creatinine clearance because of the low filtration rate caused by low T3. Anyone with kidney issues should check their thyroid function. What else won’t get filtered out? Uric acid: Does a meat diet cause gout? No, it’s the kidneys’ not filtering well. 30% of people with gout are also hypothyroid. A higher creatinine concentration, combined with a lowered filtration rate, will prevent the elimination of uric acid.

Many people following the carnivore diet are told to supplement with electrolytes. I also advise transitioning from a carbohydrate diet to a carnivore or ketogenic diet. You will lose water and so sodium with it. However, a week after you have removed the carbohydrates, meat should provide adequate electrolytes because meat has some sodium and some salt in your food. Meat has electrolytes-sodium, potassium, and chloride. Unbleached natural salt has electrolytes, sodium, potassium, and chloride. We need to add salt because most people are under enough stress to need salt or are exercising enough to need salt in their food. But it’s confusing if you have low sodium or low potassium symptoms. In those whose thyroid function isn’t optimal, the swelling, fatigue, and dizziness people experience may be caused by an imbalance in how the kidneys handle the reabsorption and regulation of electrolytes. It is something to consider if you have these symptoms.