Swelling in summer may be reactive swelling or organic lesions (e.g. kidney problems), which need to be analyzed specifically. 1. Reactive swelling: When the temperature is high in summer, it can cause the blood vessels in the skin to dilate, and body fluids penetrate through the dilated blood vessels and accumulate in the subcutaneous tissue, thus swelling occurs, and it will disappear when the temperature drops after summer. Resting in the shade and appropriate activities can help relieve reactive swelling. 2. Organic lesions: In summer, the temperature is high and sweating is large, so fluid intake will increase. If there are kidney problems, such as glomerulonephritis, the glomerular filtration rate is impaired, and a large amount of ingested fluid can not be discharged, which will lead to edema. Kidney function, urine routine and other tests can assist in making a clear diagnosis. If swelling occurs in the summer, it is recommended to consult a doctor in time to avoid delaying the condition, except for organic lesions.