Cold medicines are harmful to the stomach because the drugs used to treat colds mainly involve symptomatic treatment and the selection of antiviral medications for etiological treatment. Colds often come with symptoms like headaches and fever, thus necessitating the use of non-steroidal anti-inflammatory analgesics. The most common adverse reactions to these drugs are gastrointestinal reactions. Therefore, taking cold medicines can easily harm the stomach, especially in patients with indigestion, chronic gastritis, or gastrointestinal ulcers, who may experience more pronounced symptoms. It is recommended to take cold medicines half an hour after eating to reduce their irritative effects on the gastrointestinal tract.