Whether you’re starting on insulin for the first time or switching from one type of insulin to another, you need to be under the care of your endocrinologist. Stopping, switching medicines, or changing your insulin dose without your doctor’s guidance can lead to serious health risks.

Because type 2 diabetes needs very close monitoring, you’ll see your doctor about once every . Here are five reasons why it’s important for you to keep all of your appointments.

1. Poor blood sugar control can lead to complications

When you’re not on the right type and dose of insulin, your blood sugar control can suffer. Taking too little insulin can lead to high blood sugar levels. High blood sugar can have long-term health effects, increasing your risk for these conditions:

  • heart disease, including heart attack and narrowing of your arteries
  • nerve damage that causes numbness, tingling, burning, or pain in your feet and hands
  • kidney damage that may require dialysis or a kidney transplant
  • eye damage that could lead to blindness
  • skin infections

Low blood sugar (hypoglycemia) can be an issue if your insulin dose is too high. Problems linked to low blood sugar include:

  • shakiness
  • blurred vision
  • dizziness
  • confusion
  • weakness
  • fast or irregular heartbeat
  • seizures
  • unconsciousness

Your doctor can monitor your blood sugar with regular A1C tests. Your A1C level gives you an average of your blood sugar control over a three-month period. If your levels are off, your doctor can suggest changes to your insulin type or dosing regimen.

2. You need to know your blood sugar goal

To keep your blood sugar in a healthy range, you need to know your target numbers. Everyone’s goal is slightly different. Your doctor can help you figure out your ideal blood sugar levels based on your health, diet, exercise habits, and other factors.

They will also tell you how often and when to test your blood sugar. Your blood sugar goals and testing frequency needs can change over time. That’s why it’s important to discuss your blood sugar range with your doctor at every visit.

3. Your insulin needs can change

Your blood sugar levels can shift up or down based on things you do every day. Weight gain or loss, pregnancy, and a change in activity level can all affect your blood sugar, and how much insulin you need to control it.

Here are a few things that can raise your blood sugar:

  • food, especially if your meal is high in carbohydrates
  • lack of exercise
  • certain medicines, such as antipsychotic drugs
  • infections
  • stress
  • menstrual periods if you’re a woman

Factors that can lower your blood sugar include:

  • lack of food, or eating fewer carbohydrates than usual
  • exercise
  • alcohol
  • side effects from medicines

You may need to fine-tune your insulin dose to accommodate these factors. Your doctor can make sure any adjustments to your medicine are made safely.

4. Insulin can have side effects

Like any drug you take, insulin can have side effects. Some of these effects are minor — like redness or soreness at the injection site. But if you take too much insulin, you can have symptoms of low blood sugar. These include:

  • weakness
  • fast heartbeat
  • dizziness
  • fainting

Insulin can also interact with other drugs you take. Whenever you switch to insulin or to a new type of insulin, ask your doctor what side effects it can cause and what to do if you have side effects.

5. You need to make sure you’re doing it right

Insulin comes in several forms: syringe, pump, pen, and inhaler. Each dosing method comes with its own set of instructions. If you don’t follow all the steps correctly, you could get more or less insulin than you need. That could cause side effects.

Every time you go on a new medicine, including insulin, you need to have a meeting with your doctor. Ask how this insulin is different from the medicine you were taking. Find out:

  • what dose to take
  • when to give yourself the injection
  • where on your body to give the injection — belly, arm, buttocks, etc.
  • how to give yourself the injection, including what angle to use
  • how to store your insulin
  • how to dispose of the needle

It can help to also have a certified diabetes educator talk you through the process of administering insulin.