1. The initial stage of chronic renal failure:

The patients with renal failure have no symptom and the abnormality of renal function can only be detected through laboratory examinations.

2. The early and middle stage of chronic renal failure:

In this period, blood routine examination of patients with chronic renal failure should be done. If the level of urea nitrogen grows high, the patients may have some slight symptoms. For patients with renal failure, they may need to urinate for several times during the night, which affect their sleep, because their kidneys can hardly absorb moisture from urine and concentrate it as normal at nights. Clinically, the patient with renal failure will have symptoms like frequent urination and increased nocturia. At the same time, patients with chronic renal failure also suffer some complications like hypertension and edema, because their kidneys can not discharge too much salt and water. Hypertension may also bring apoplexy and cardiac failure to patients with chronic renal failure.

3. The final stage of chronic renal failure:

If the patients’ conditions are not under effective control and toxins gradually accumulate in their blood, symptoms like physical weakness, fatiguability, slow reaction, etc will be resulted. With the gradual increase of toxic substances, patients may suffer from some intramuscular and neural abnormalities such as muscle twitching, muscle weakness, spasm and so on. At that time, needle-stab-like pain will arise at the end of limbs and even worse, some parts of the body may lose feelings. For those patients, if their hypertension is too high or there are some toxic substances in their blood, it may lead to brain dysfunction and trigger convulsions (epilepsy) eventually.