What are the symptoms of acute kidney failure?
In many cases, acute kidney failure begins with non-specific symptoms such as rapid fatigue, difficulty concentrating and nausea. Urination decreases, which means that those affected hardly feel the need to go to the toilet. If the amount of urine excreted is less than 500 milliliters in 24 hours, doctors speak of oliguria. If the affected person excretes less than 100 milliliters of urine in the same period, this is anuria.
In some cases, however, acute kidney failure causes no symptoms at all.
The reduction in urine excretion leads to water retention in the tissue, known as edema. This mainly occurs in the legs. Later, the water that is no longer excreted by the diseased kidneys also accumulates in other organs. If the lungs are affected (pulmonary oedema), this usually results in shortness of breath.
Acute renal insufficiency also changes the composition of the blood salts (blood electrolytes). The increase in potassium levels is particularly important: hyperkalemia can lead to life-threatening cardiac arrhythmia, dizziness and brief loss of consciousness.
What are the symptoms of chronic kidney failure?
The symptoms of chronic kidney failure (chronic renal insufficiency) depend primarily on the underlying disease (such as diabetes or high blood pressure) in the early stages of the disease. In later stages of the disease, on the other hand, the secondary diseases resulting from the kidney failure characterize the clinical picture.
Initial stage
Initially, chronic renal insufficiency does not cause any symptoms for a long time: as long as kidney function is only slightly impaired, the person affected usually does not notice anything. Some people complain of uncharacteristic symptoms such as poor performance and tiredness. Another early sign of chronic kidney failure in some cases is frequent urination, whereby the urine is very pale and not very concentrated.
Advanced stage
As it progresses, chronic kidney failure is often accompanied by the following symptoms:
- High blood pressure (hypertension) – occurring for the first time or becoming increasingly difficult to control
- Small amounts of urine (less than half a liter per day – normal is about one and a half liters per day)
- Sometimes red-colored urine (due to breakdown products of the red blood pigment)
- Foaming urine when urinating (indication of protein in the urine)
- Fluid retention (edema) in the body, especially in the legs and eyelids
- Anemia (renal anemia) and associated fatigue, weakness, concentration problems, decreasing physical resilience as well as paleness or café-au-lait coloration of the skin (dirty yellow skin coloration)
- Bone pain
- muscle pain
- Itching and burning in the legs
- Gastrointestinal complaints such as nausea, vomiting and diarrhea
The progression of chronic kidney failure gradually damages almost all organs and organ systems in the body – doctors refer to this as uraemic syndrome. It leads to pathological changes in the cardiovascular system, the hematopoietic system, the gastrointestinal tract, the nervous system, the endocrine system as well as the skin and bones.
The more the kidneys lose function, the more serious the symptoms become. In terminal kidney failure (end stage), symptoms such as severe shortness of breath, irregular heartbeat, drowsiness, dizziness, convulsions and coma become apparent.
