Disturbances in blood purification as well as in the water and salt balance affect many other organs of the body. Chronic kidney weakness can therefore lead to various complications:
High blood pressure
A significant consequence of chronic kidney weakness is increased blood pressure: about 80% of so-called kidney patients suffer from it. However, high blood pressure can also be the cause of kidney weakness. As the production and excretion of urine decreases, the body can no longer get rid of excess salt and water, which causes blood pressure to rise. It also leads to fluid retention, especially in the legs (edema). In extreme cases, fluid accumulates in the lungs, leading to coughing with whitish to foamy secretions and severe shortness of breath (pulmonary edema).
Heart failure, cardiac arrhythmia, heart attack, stroke
In addition, there is further damage to the cardiovascular system, especially a pronounced calcification of arteries and also of heart valves. Thus, heart valve defects or cardiac insufficiency can occur as a result of chronic kidney weakness, but of course also heart attacks and strokes due to the calcified arteries. The kidneys increasingly lose the ability to excrete potassium when they fail.
Particularly when the daily urine volume is less than one liter, the potassium levels in the blood can rise (hyperkalemia), which is manifested by a slowed heartbeat, dizziness and brief loss of consciousness as well as muscle weakness and tingling sensations. If potassium levels are greatly increased, there is a risk of cardiac arrhythmia and even cardiac arrest. The excess water can also lead to a heart attack or stroke.
Disorders of the nervous system
Neurological disorders are also a common complication of advanced chronic kidney weakness. They can be measured as slowed nerve conduction velocity and altered brain waves in the electroencephalogram (EEG). Possible symptoms are:
fatigue, memory and concentration problems
Optical hallucinations, disorientation, coma
itching, burning, muscle cramps or muscle weakness
When kidney function weakens, lower amounts of the blood-forming hormone erythropoietin are also produced. This leads to anaemia, the so-called renal anaemia, which can manifest itself by increased fatigue, a conspicuous paleness of the skin and a decrease in physical resilience.
Disorders of bone metabolism
As kidney function decreases, the body also has less active vitamin D at its disposal. Active vitamin D is a hormone that promotes the absorption of calcium via the intestines and the strength of the bones. If too little active vitamin D is produced in the kidneys, the calcium content in the bones decreases, more bone fractures occur and more bone, muscle and joint pain occurs. Since the damaged kidneys also excrete less phosphate, the phosphate level in the blood increases, which further promotes the decalcification of the bones and the calcification of the arteries.
High phosphate levels in the blood cause itching, bone pain and muscle aches. In addition, the increasing accumulation in the body increases the risk of arteriosclerosis. This increases the risk of heart attack and stroke.
Disorders in protein and energy metabolism, hormonal disorders as well as nausea and loss of appetite are the reason why many patients with kidney weakness are malnourished. Especially the protein metabolism is affected. As the kidney function decreases, the body absorbs less protein, and calorie intake may also decrease.