Hospitals can save you, but they can also harm you. So how can you stay safe in hospitals? Follow these 12 life-saving tips:

1. Never go alone. Always bring someone else—a trusted family member or friend—with you. That person will be your primary advocate, and can serve as an extra set of eyes and ears to help make sure you are safe. (This tip applies to routine doctors’ appointments too; always bring your advocate with you.)

2. Determine, in advance, the goals of the hospitalization. Before you go to the hospital, ask your doctor why you need to be hospitalized. Is it necessary, or is outpatient care possible? What is the goal of the hospital stay? How often will that goal be assessed? Can you choose which hospital to go to, and when you should go? Rarely is the need for hospitalization so emergent that you can’t get these answers and discuss them with your doctor in advance.

3. Prepare. Bring all the things you would normally bring with you to a doctor’s appointment, including a list of your medical problems and allergies. Don’t assume that the hospital will have your records. It’s very important to bring all the pill bottles that you take so that there will be no mistake about what dosage and how often you take your medications. Keep your main doctor’s phone number and your advocate’s phone number handy (though your advocate should be going with you to the hospital).

4. Meet your care team. Find out who is in charge of your care: is it your regular doctor or a hospitalist doctor? Introduce yourself to her, and to your primary nurse. Meet the patient care tech, the nursing assistant, and the other members of your healthcare team. Tell them about yourself, and find about them. The more they get to know you as a person now, the more they will help to answer your questions later. Your advocate should also get to know your care team.

5. Know who to call for help and how. Who will be the night-duty doctor and nurse, and how can you reach them? If you are in trouble, or if your advocate sees you’re in trouble, how will you get help? Many hospitals have a “rapid response team” or a “code team” that come to assist in emergency situations. Can your advocate activate this team himself?

6. Ask about every test done. Don’t just consent to tests. They all have risks, so ask about them. Why is your blood drawn every morning—what is the purpose? Why are you getting the CT scan? You should discuss every test with your doctor in advance of doing them, and have a thoughtful discussion about risks, benefits, and alternatives.

7. Ask about every treatment offered. If you’re being started on a new medication, ask about what it is, what the risks are, what the alternatives are, and why you need it. If you’re told you need a procedure, make sure you discuss it with your doctor.

8. Keep a record of your hospital stay. Your advocate may need to help you with keeping a careful record. This includes your tests (make a note of what you get done and ask about the result), medications (write down when each medication is given and double-check it’s correct), and providers who come to see you (write down names of specialists and their recommendations). A detailed record helps to prevent mistakes, coordinate your care, and keep you on track.

9. Attend bedside rounds. Doctors and nurses usually have rounds at least once a day to discuss their patients. Find out when rounds happen and ask if you and your advocate can attend. This is your time to find out what’s going on with your care. Prepare questions to ask during rounds.

10. Know your daily plan. Rounds are a good time to ask about what is happening that day. Are you doing more tests? More treatments? Are you on track, or did something unexpected happen? When can you expect to go home?

11. Keep your eye on infection control. If someone comes into your room, ask him to wash their hands. If someone is doing a procedure on you, ask her to follow an infection control checklist. Hospital-acquired infections kill 100,000 people every year, and you can help prevent them.

12. If something isn’t right, speak up immediately. Remember that it’s your body and you know yourself the best. Get help if you develop new or worsening symptoms. Empower the person you’re with to speak up for you if you can’t.

All of these tips may sound like a lot of work, and you may be wondering why it’s your job to do all of this. After all, aren’t you the patient, the person who is feeling unwell and seeking help? By and large, doctors and nurses are well-meaning, and most of the time, the system is working well and you will get good care. However, mistakes do happen—and you and your advocate can help prevent medical error. Follow the tips above to make sure that you are safe and well during every hospital stay.

Leana Wen is an emergency physician who blogs at The Doctor is Listening. She is the co-author of When Doctors Don’t Listen: How to Prevent Misdiagnosis and Unnecessary Tests.  She can also be reached on Twitter @drleanawen.