Laryngeal cancer refers to malignant tumors that occur in the larynx. The most common symptoms include hoarseness, difficulty in breathing, cough, difficulty in swallowing, and lymph node metastasis in the neck. Generally speaking, laryngeal cancer can be divided into four types: supraglottic laryngeal cancer, glottic laryngeal cancer, subglottic laryngeal cancer and transglottic laryngeal cancer. For supraglottic laryngeal cancer, there are usually no obvious symptoms in the early stage, and some patients may feel slight sensation only when the tumor has developed to a considerable extent, such as foreign body sensation in the throat and swallowing discomfort. On the other hand, early symptoms of laryngeal cancer of the vocal hilar type are more obvious, mainly the change of voice, such as hoarseness, easy fatigue and weakness of pronunciation, which can be easily misdiagnosed as laryngitis. Subglottic laryngeal cancer is generally less common because the location of the mass is hidden and the early symptoms are not obvious, so it is not easy to be detected during clinical examination. Transglottic laryngeal cancer is also not easy to be detected in early stage, and the clinical symptoms are not obvious. Moreover, this type of tumor develops slowly, and it usually takes more than 6 months from the appearance of the first symptoms to the definite diagnosis. Therefore, for the diagnosis of laryngeal cancer, if you are older than 40 years old, have long-term smoking, drink a lot of alcohol and have obvious hoarseness, you must do electronic laryngoscopy; for patients who do not have hoarseness but have other throat symptoms and smoke and drink a lot, it is better to do electronic laryngoscopy to exclude the possibility of laryngeal cancer.