Low creatinine is generally referred to as low blood creatinine. Most patients with low blood creatinine are simply weak or thin, usually without disease, and in a few cases are associated with malnutrition, muscle wasting, or uremia. Creatinine is a metabolite produced by muscle metabolism and released into the blood, which is excreted through the kidneys in the urine and can indicate renal excretory function. It can usually be measured by blood or urine tests, and normal blood creatinine is usually: 44-133 μmol/L. Low blood creatinine is commonly found in cases where people are on a diet or on a long-term vegetarian diet, and their protein intake is insufficient, resulting in lower creatinine levels. Low creatinine may also be related to some diseases. Commonly, for example, patients with malnutrition and muscle atrophy produce less creatinine due to their own low muscle volume, which results in low creatinine levels in the blood; patients with uremia also have low creatinine due to the large amount of creatinine excreted through the urine. In addition, low blood creatinine can also occur in cases such as pregnant women, low exercise, thin individuals, other major illnesses and serious diseases, and trauma. In the case of low blood creatinine, it is recommended to first actively treat the primary disease, and at the same time consume some food rich in high quality protein to supplement nutrition, and also strengthen exercise to increase muscle mass.