These teas are harmful to the human body.

Strong Tea

Strong tea contains large amounts of caffeine, theophylline, and other stimulating substances. Drinking strong tea can lead to insomnia, headaches, tinnitus, blurred vision, and is also bad for the stomach. Some people may even experience nausea.

Moldy Tea

Moldy tea contains a large number of toxins.

Contaminated Tea (Tea with Foreign Odors)

Some odors are toxic, such as paint or camphor.

Over-roasted Tea

Tea leaves that have been roasted excessively lose their nutrients and have a poor taste.

Overnight Tea

Overnight tea, especially if it has developed an off-flavor, often harbors and breeds a large number of bacteria, even if the change in taste is not yet noticeable.

Over-steeped Tea

When tea is steeped for too long, many substances harmful to the human body are leached out.

Cold Tea

Tea is best consumed warm. Cold tea can cause stagnation of cold and accumulation of phlegm in the body.

Scalding Hot Tea

While tea is typically brewed with boiling water, it should not be consumed when excessively hot. Overly hot substances are extremely harmful to the stomach and intestines.