Pu'er Tea has certain effects such as aiding digestion, reducing greasiness, promoting diuresis, and relieving constipation. However, it is not suitable for individuals with nerve weakness, weak digestive systems, liver diseases, and women during menstruation should also avoid drinking Pu'er tea.

1. Nerve Weakness: Pu'er tea contains Caffeine which can stimulate the central nervous system. Drinking Pu'er tea may cause insomnia in people with nerve weakness, so this group of people should avoid drinking Pu'er tea.

2. Weak Digestive System: Pu'er tea can increase the secretion of gastric acid. For people with a weak digestive system, it can exacerbate discomfort symptoms, especially for those suffering from gastric ulcers. Therefore, people with a weak digestive system should avoid drinking Pu'er tea.

3. Liver Diseases: Most of the substances in Pu'er tea, such as caffeine, are metabolized by the liver. Drinking excessive amounts of Pu'er tea may exceed the liver's metabolic capacity and potentially cause liver damage if you have liver disease. Therefore, patients with liver diseases should avoid drinking Pu'er tea.

4. Menstrual Period: Pu'er tea contains a large amount of tannins, caffeine, and other components. During menstruation, the body's immune system is relatively weakened and mood is low. Drinking Pu'er tea may increase feelings of anxiety and restlessness. Therefore, women should try to avoid drinking Pu'er tea during their menstrual period.

Therefore, Pu'er tea is not suitable for all populations. Before drinking, one should determine whether it is safe to do so to avoid any uncomfortable symptoms.