One of the most frequent questions that surgeons are asked is when a patient can start driving, or return to work or school. Believe it or not, there isn’t a secret formula for this. Every patient is different. When doctors quote a certain number of days from the time of surgery to resuming normal activities, they’re basing that decision on a few factors. Here are some basic rules.

Don’t Drive or Go Back to Work or School if You’re Not Thinking Straight

When doctors release a patient to go back to school or to work, they want to be sure that the patient won’t get himself or herself into trouble there. We don’t want our patients to make a bad business decision or fail an exam because they went back to their regular routine too early. There are a couple of effects that your doctor will take into account when considering whether you’re ready to go back:

• The effects of anesthesia: Any operation that requires general anesthesia is likely to leave you feeling pretty low for a few days. Patients describe the effects of anesthesia as feeling as though they’re in a cloud, or fuzzy-headed. How long you have that feeling is related to how much time your operation took. The effects of anesthesia can last longer if you have a major abdominal operation, where paralytic drugs are used, or an operation requiring the use of a heart-lung bypass machine. Regardless, the effects of anesthesia can leave you not thinking straight, which is no condition for working or studying.

• Narcotic pain medications: Operations require different degrees of pain medication, and it’s very common for patients to require some prescription narcotic pain medications after surgery. The expectation is that you will use less and less as the days go by. Because narcotic pain medications can affect you much the same way that alcohol does, you shouldn’t drive, work, or go to school while taking them.

Don’t Drive or Go Back to Work or School if You Can’t Move Properly

Driving a car requires that you be able to turn your head and body, that you be able to move your feet and hands without difficulty or pain, and that your mind be clear enough to notice that truck that stopped suddenly in front of you. The same goes for work or school: There are some physical tasks that can’t be avoided, and you need to be able to do them without the help of narcotic pain medications before you return to your usual routine.

Beyond that, there are a few special situations that you should be sure to talk to your doctor about (if they apply to you):

• Contact sports: When patients can return to playing contact sports is a common question. All the above restrictions apply, of course, but additional time – usually about 6 weeks – is needed before surgical wounds are strong enough to withstand a tackle, kick, or slide into second base. The size of your visible wounds might not be the determining factor, because your surgeon must also consider the stitching inside your body. Some wounds may take longer – or even make contact sports off limits for life – so it’s very important to discuss any return to sports or physical education with your surgical team. Similarly, many schools won’t allow a student to participate in sports after surgery until they’ve been cleared with a doctor’s note, so be sure to remind your surgical team to provide one when the student is cleared to participate.

• Light duty: Along the same lines as restrictions on contact sports are restrictions on the sorts of work you can do when you’ve met the basic qualifications to leave the house. Especially after abdominal operations, where lifting heavy objects can increase the pressure in your abdomen and re-open your incisions, your surgery team will probably recommend that you do light duty. That usually means office work only – nothing that would require physical strain. The timeframe varies, and there are no hard and fast rules. As with contact sports, light duty restrictions are usually in place around 6 weeks to allow your scars to build up the strength they need to withstand your pre-operative level of activity.

The Most Important Guide is Your Own Body

As with many things in medicine, the timing of your return to the driver’s seat, work, and school is an inexact science. Your doctors can only make informed guesses about when you’ll be ready to resume your regular activities. It’s important to follow their instructions to make sure that you give your body time to heal. But the best judge of your readiness is your own body – no matter whether your doctors say you’re ready, if something feels wrong or painful, stop right away.

This story originally appeared in the  Health Dialog Care Compass Blog.