What are the symptoms of quitting smoking?

After quitting smoking, the body may experience a series of symptoms, mainly manifested in the following aspects: 1. **Nervous system symptoms**: Such as headache, finger tremors, mood swings, anxiety, irritability, anger, insomnia, difficulty concentrating, and slowed thinking. These symptoms occur due to the long-term effects of nicotine in tobacco on the nervous system, and the nervous system needs time to adapt to a nicotine-free environment after quitting smoking. 2. **Respiratory system symptoms**: Coughing and sputum production may worsen, especially with the expectoration of black-gray phlegm. Dryness and itching in the throat may also occur. This is because the respiratory tract begins to clear harmful substances accumulated over years of smoking after quitting. 3. **Digestive system symptoms**: Symptoms such as dry mouth, thirst, increased or decreased appetite, constipation, or diarrhea may appear. These are normal reactions that occur as the body adapts to a new environment without tobacco stimulation. 4. **Circulatory system symptoms**: Some individuals who quit smoking may experience increased heart rate and elevated blood pressure. However, these symptoms will gradually return to normal as the body adjusts and adapts.