Unnormal red lips may be caused by suffering from diseases such as lipitis and allergic skin diseases; it may also be caused by carbon monoxide poisoning and other reasons. 1. Lipitis: Frequent eating of spicy and stimulating food, frequent stimulation of the lips by chemical substances may induce lipitis, resulting in abnormal red lips of the patient. It may also be accompanied by symptoms such as swelling, flaking, itching and dryness of the lips. 2. Allergic skin disease: If the lips are exposed to allergens, it is easy to cause the lips to suffer from allergic skin disease, so that patients appear abnormal red lips, itching lips and other symptoms. If you can not specify the allergens, you can go to the hospital for allergen testing, and then avoid re-exposure to allergens to prevent aggravation of the condition. 3. Carbon Monoxide Poisoning: If you are in the environment of gas leakage for a long time, you will be prone to carbon monoxide poisoning, which will make the patient suffer from dizziness, nausea, vomiting, fatigue, etc. If the poisoning is moderate, the patient may suffer from dizziness and nausea. If the poisoning is moderate, the patient may appear flushed, lips cherry red and other symptoms. If the lips are not normally red there may be other reasons, it is recommended that patients go to the hospital to clarify the cause of the disease and receive treatment as soon as possible.