Because of long security lines, flight delays and cancellations, traffic, and big crowds, travel can be stressful under any circumstances. Add a thyroid condition into the mix, and the journey becomes that much more complicated.

Hypothyroidism doesn’t have to disrupt your travel plans. You just need to plan ahead.

About four to six weeks before you leave, check in with your primary care doctor or endocrinologist. Make sure your hypothyroidism is under good control, so you don’t have to worry about getting sick while you’re on vacation. Ask whether you need any vaccinations if you’re going to be traveling to another country. Get written instructions on how to handle any health issues that might arise while you’re away.

Book flights at times when you tend to feel your best — whether that’s in the morning or early afternoon. Avoid peak travel times when airports and train stations are most crowded. Before you leave, identify the hospital and doctors’ office closest to your hotel. And while you’re away, plan rest breaks throughout your day to avoid getting overtired.

If you need levothyroxine (Levothroid, Levoxyl, Synthroid) to keep your thyroid hormone levels in a normal range, you have to take it every day. Bring enough to last your whole trip — plus a few extra pills in case you get stuck at your destination because of a flight cancellation or bad weather.

Pack the medicine in its original container and put it in your carry-on bag. That way, if your luggage is lost, you won’t be without your medicine.

Stay on your regular dosing schedule. You might have to adjust to a time difference, but try to take your medicine at the same time of day as you did at home.

Bring a copy of your prescription with you. This is especially important if you’re traveling abroad. Some countries require that you show a prescription to bring in medicine. You’ll also need a prescription if you lose your medicine and have to refill it at a local pharmacy.

Before you leave for an overseas trip, check with the American embassy or consulate to make sure the country you’re visiting will allow you to bring in the medicines you take. Some countries have restrictions on the types of medicines visitors can bring in.

Bring your doctor’s phone number and email address, just in case you need verification for a foreign pharmacy to refill your prescription. Leave a copy of your doctor’s contact information and your insurance plan numbers with a friend or family member. It’s also a good idea to bring a letter from your doctor that explains your condition and the medication you take to treat it.

Find out what travel services your health insurance plan includes. For example, if you need to visit a doctor or go to the hospital while you’re away, will it cover the cost? If not, you might want to consider buying supplemental travel health insurance. Look into a plan that includes evacuation insurance, which will pay for your transportation back home if you become seriously ill. You might also want to consider buying trip cancellation insurance, which will reimburse you for the costs of your vacation if you get too sick to travel.

Before you go, sign on with a medical alert company. They’ll give you a necklace or bracelet, and a wallet card with your name, health conditions, and a toll-free number that health care professionals at your destination can call to learn more about your medical situation. A medical alert tag could save your life if you’re unconscious and unable to explain your condition to doctors and paramedics.

Drink extra water throughout the day, both while you’re on the plane and once you arrive at your destination. Avoid foods and drinks that can dehydrate you, like salty snacks, soda, and coffee. Staying hydrated can prevent constipation, which is already a problem in people with hypothyroidism.

When you travel, you’ll be on your feet a lot — and you’ll sit a lot. Wear loose, comfortable clothing and low-heeled shoes. On the plane, get up once every hour and walk around to stretch your legs. Staying active will help prevent blood clots from forming in your legs.

If you do get a little dried out, bring along an emollient moisturizer to rehydrate your skin. Apply it every morning when you get out of the shower or bath, to hold moisture in your skin.

Remember: Although travel planning and prepping with hypothyroidism in mind may take some extra steps, don’t let that prevent you from taking a trip. In fact, advance planning may ease any anxieties you have about traveling with your condition.