A raised level in the blood of Urea is the nitrogen-containing breakdown product of protein metabolism. The nitrogen from the proteins is converted to ammonia in the liver, which is combined with carbon dioxide to form urea. This is continuously excreted via the kidneys but also via sweat. Urea is one of... and other urinary substances, which in chronic kidney disease can no longer be adequately excreted due to impaired renal function (The glomerular filtration rate (GFR) is defined as the volume of fluid that is filtered by the glomeruli of the nephrons of both kidneys per unit of time to produce primary urine. It is, therefore, the chief measure of kidney function. The rate corresponds to...). This leads to renal damage due to Toxic, nitrogen-containing urinary substances responsible for uraemia and kidney damage...., toxic urinary substances The symptoms of uraemia are itching, gastrointestinal problems, nausea, vomiting, bleeding due to inflammation of the gastric mucosa (gastritis), intestinal inflammation, pericarditis, water in the lungs (pulmonary Excess fluid collecting in the tissues of the body, which can cause them to become swollen....) accompanied by shortness of breath, neurological disorders (from tremors to coma), impairment of blood production (potentiallyanaemia), and bad breath. Can also cause changes in muscles, stiffness, abnormal movements, aversion to movement, aversion to eating, fatigue, lethargy and weakness.