We often see or hear such things around us: ear drops to the ears for ear pain, ear drops to the ears for ear itching, ear drops to the ears for running pus, and some even apply so-called prescriptions for certain herbs ground into powder, fragrance oil, etc. into the ears, but as a result, many patients not only have no effect but also aggravate their symptoms, with serious symptoms such as headache, ear stuffiness and obstruction, and hearing loss. It seems that ear drops should not be used casually. In order to use them correctly and avoid aggravating or complicating the condition due to improper use of ear drops, it is necessary to know the causes of ear pain, ear itching and running pus in the ears, and then choose the correct ear drops for the cause and apply the correct method to the ears. First of all there are two main causes of ear pain: one is infectious and the other is neurological. There are two main types of infectious diseases that cause earache, depending on the location of the infection: one is otitis externa or external ear canal boil, which occurs in the external ear canal and is mostly caused by digging or water ingress in the ear; the other is otitis media, which occurs in the middle ear and is mostly caused by improper blowing of the nose or coughing from pharyngitis and bronchitis, etc. The pathogenic bacteria enter the middle ear through the tube between the middle ear and the nasopharyngeal cavity, which is medically called the eustachian tube. This is called the eustachian tube and causes otitis media. In children, the eustachian tube is relatively short, wide and flat compared to adults, so children are more likely to get otitis media after a cold or pharyngitis respiratory infection. For ear pain caused by such infectious diseases, it is correct to apply anti-inflammatory ear drops, and the commonly used drug in clinical practice is oclofloxacin ear drops. Earache caused by neurological diseases is usually paroxysmal pinprick-like or throbbing or pulsating pain, which is different from the persistent swelling, dull pain, pulling the auricle or pressing the ear screen to aggravate the pain of infectious diseases. Neuropathic otalgia can be caused by acute pharyngitis, tonsillitis, gingivitis and other diseases through nerve reflexes, or it can be primary with no cause. Another disease is herpes zoster in the ear, which is commonly referred to as serpentine, and most of them are caused by a decrease in the body’s resistance leading to the invasion of the nerve by the herpes zoster virus that is latent along the nerve. This disease is easily missed when herpes is not yet present in the ear. There is no need to apply ear drops for this type of neuropathic earache. The exception is when herpes is present in the ear or when the herpes has broken down and is combined with a bacterial infection. The first reason is that the normal secretion of cerumen in the ear, which is usually called earwax, is softened and thinned out by the water in the ear from bathing and washing the hair. The second common disease that causes pus to flow from the ear is otitis media, which is divided into two types: acute and chronic, depending on the onset. Acute otitis media is usually only acute congestion of the tympanic membrane in the early stages, with pain in the deep part of the ear as the main cause. If the condition is not controlled, the perforation of the tympanic membrane will result in pus flowing from the ear, at which point the patient will have less ear pain due to the tension of the perforated tympanic membrane. If the perforation is not healed, it will turn into chronic otitis media, which is prone to ear pus when the ear is filled with water, cold, runny nose, respiratory tract infection and the body’s resistance decreases. In this case, it is necessary to apply 3% hydrogen peroxide to clean up the pus in the ear and then put in anti-inflammatory ear drops. The third disease that can lead to running ears is eczema of the external ear canal. Another major symptom of this disease is ear itching, which is an allergic disease of the external ear canal, so this disease can be treated with anti-allergic ear drops after cleaning the secretions in the ear. In severe cases, fungal infections can be combined. Most cases of itchy ears are caused by repeated digging of the ear, which increases local sensitivity. In addition to the common eczema of the external ear canal mentioned above, another disease is external ear canal fungal disease, which is mostly caused by the abuse of ear drops. Since fungi tend to grow and multiply in a warm and humid environment, fungal infections are easily caused when water or secretions accumulate in the external ear canal and when ear drops are applied for a long time. These patients complain of itchy ears, and the secretions in the ears are often yellowish-black or grayish-white powdery or fluffy, etc., just like the appearance of moldy food in summer. Therefore, these patients can only apply antifungal ear drops, such as 1 to 2% alcohol of salicylic acid or 1 to 2% alcohol of muscimol, fluconazole drops, etc. In order to ensure the efficacy of the drops it is best to clean the discharge from the external ear canal and the surface of the eardrum before the drops are applied. The following is the correct way to apply the ear drops: The patient should sit or lie down with the affected ear facing upward; pull the auricle backward and upward, put 3~5 drops of the medication into the external ear canal, then gently press the ear screen several times with your fingers, and change the position after 5~10 minutes so that the medication is fully and evenly distributed on the surface of the external ear canal or tympanic membrane or flows into the middle ear through the tympanic membrane perforation. The following matters need to be noted when using ear drops: 1. It is best to clean up the secretions in the ear before the drops are applied. Deeper ones, especially on the surface of the tympanic membrane, need to be done by an otolaryngologist to avoid the presence of secretions in the ear from affecting the efficacy of the drug. 2.Some drugs are ototoxic such as aminoglycoside antibiotics, which can cause deafness, tinnitus and dizziness, so such drugs are clinically contraindicated. 3.Powder is not advocated to avoid blocking the tympanic membrane perforation, which may lead to poor outward drainage of pus and turn to inner ear or intracranial infection. The powder without tympanic membrane perforation will easily settle on the surface of the tympanic membrane and affect hearing. 4. Avoid using colored drops so as not to hinder local observation. 5.The use of corrosive agents containing phenols and arsenic is forbidden in the middle ear cavity. 6.The temperature of the ear drops should be made as close as possible to the body temperature in winter to avoid causing vertigo. 7. It is not easy to use antibiotic aqueous solution for a long time to avoid breeding fungus, causing fungal otitis externa and complicating the condition. To sum up, before applying ear drops, you should first clarify what kind of disease you have in your ears, and then choose targeted ear drops according to the cause. To ensure the full efficacy of the drug, it is best to clean up the secretions in your ears before putting the drops into your ears, and if necessary, you need a professional doctor to clean them up, especially if you have a long medical history, or if you have bacterial or fungal cross-infection or accompanying eczema, you need a professional doctor to guide the diagnosis and treatment. In order to avoid the various ear diseases mentioned above, it is important to avoid ear digging, water in the ear, improper nose blowing and abuse of ear drops.