The hiccups from smoking are probably due to the smoke from smoking and the nicotine in the smoke stimulating the vagus nerve and causing the diaphragm to spasm. It is recommended that you slowly drink a glass of hot water to relieve the symptoms, and you can also use the breath-holding method to relieve hiccups, such as holding your breath for 30 seconds after inhaling deeply, and then exhaling several times, which generally relieves the symptoms. In addition, most of the smoke from smoking enters the stomach and stimulates the stomach causing diaphragm spasms and hiccups, and smoke also tends to stimulate the stomach causing increased secretion of gastric acid. The smoke contains many kinds of toxins inhaled into the stomach or lungs, which can easily cause diaphragm spasm and hiccups, so it is advisable to quit smoking to avoid affecting your health.