I think almost everyone has been ill at least once in his life, and even those lucky few who are never ill sometimes have to visit a doctor. So everyone shares this experience.
When you are not well, you go to the doctor. For example you do not sleep very well or you have a cough. You may have a pain in your chest, a headache, a stomach-ache, a sore throat, a cold or something more serious. The doctor usually says that you need an examination. He looks at your tongue. Doctors can see at once if something is wrong by your tongue. Then the doctor examines your throat. He says: "Open your mouth. Say "Ah". You say it two or tree times. The doctor feels your pulse. If your pulse is faster than normal it is another sign or, as doctors say, symptom that you are unwell. Sometimes the doctor wants to know your temperature. The normal temperaure is 36,6. A higher temperature indicates some disorder in your body. You take off your coat and unfasten your shirt and the doctor listens to your heart and chest. Then he is ready to say what is the matter with you.
In some cases there is nothing really serious wrong with you. Then the doctor just tells you to rest and stay at home for a day or two. In case of real trouble doctor prescribes some medicine.
Usually you take the prescription to a chemist's. Chemist's shops are also called pharmacies. In the United States people preparing and selling medical goods are called druggists. A chemist's shop in America is a drug-store. Chemists make up medicines according to the doctors' prescriptions, or sell ready-made medicines or drugs. You buy what has been prescribed by your doctor and the chemist usually tells you how to take your medicine. It can be a tablet or some tablets two or three times a day. Some medicines are taken before and some after meals. With liquid medicines we usually take a spoonful before having a meal.
Sometimes you don't feel well enougth to go to the surgery. For example, people call a doctor when they have a very high temperature. In this case the doctor comes to your house and examines you there. He leaves some prescriptions for you and your relative or friend goes to the chemist's to buy the necessary medicines.
If it's serious, for example a heart attack, or an accident, then it needs urgent medical assistance and you call an ambulance. The ambulance arrives with a doctor who examines the person and gives him the aid he needs. In most cases the person is taken to hospital for a more intensive examination and therapy. When an operation is required it is performed by a surgeon.