Plasma protein content is higher than tissue fluid is generally normal. 1. Under normal circumstances, the protein content of plasma is to be more than the protein content of tissue fluid, because protein is a large molecule, and the vascular wall has selective permeability, protein generally can not pass through the vascular wall into the tissue fluid, so the plasma contains more protein, while the tissue fluid and the protein content in the lymph is relatively small. 2. The proteins in plasma are generally referred to as plasma proteins, of which albumin is the most abundant, has the function of maintaining the osmotic pressure of plasma colloid, and will also be combined with a variety of free fatty acids, bilirubin, sex hormones, thyroxine, adrenaline, and other ligands or substances to play a transport function, which plays an important role in the maintenance of the normal physiology of the human body.