If you take medicine for a chronic condition and you fast, you need two conversations before the fast day arrives. The first is with your clinician, who knows your body and your medicines. The second is with your rav, who knows your community's practice and can apply the medical facts to the religious question. This checklist walks you through the timing and the questions, anchored to Yom Kippur, which begins at sundown on Sunday, September 20, 2026 [2].
Preservation of human life overrides the commandments. Peninei Halakha states that on Yom Kippur even the infirm are obligated to fast because it is a Biblical command, and that only people whose lives may be in danger if they fast are exempt [1]. On the other fasts, which were instituted by the Rabbis, anyone who is sick is exempt from fasting even if the condition is not life-threatening [1]. Peninei Halakha records the view that Tisha B'Av differs from the minor fasts, with only someone who is actually sick or liable to become sick because of the fast exempt, while even someone in great pain is exempt from the minor fasts; it also records that many poskim do not make such a distinction [1]. Whether your condition puts you in danger is a medical question for your clinician and a religious question for your rav.
The clinician conversation comes first
Your clinician knows your condition, your medicines, and how your body responds to them. They can tell you whether fasting poses a medical risk and what warning signs should end the fast immediately. Start this conversation at least 3 weeks before the fast. Your clinician needs time to think, and you need time to bring the answer to your rav.
The question is specific: can your body and your condition go without food and water from sundown to nightfall? Not whether you want to fast, not whether you have fasted before, not whether you feel strong that day. Whether this body and this condition can safely do it. Your clinician may say yes, no, or maybe with conditions. Write down the answer.
Ask what warning signs mean you should break the fast immediately. Dizziness, chest pain, severe headache, loss of consciousness, blood sugar below a certain number, blood pressure above a certain number, or something else specific to your condition. Ask your clinician to name the signs so you know them before the fast day. Write them down and bring them to your rav.
Ask whether your medicines need water to swallow. Peninei Halakha states that sick people who need to take medicine regularly must continue taking their medicine even on a fast day; that if possible one should swallow it without water; that almost no medicine does any harm to those who take it without water; and that one who cannot swallow pills without water should add something bitter to the water until it becomes undrinkable and use it to swallow the pill [1]. Your clinician and your pharmacist can tell you which of your medicines can be swallowed dry and which ones cannot.
Ask whether any medicine should be taken differently on a fast day. Some medicines work better with food. Some need to be taken at a certain time. Some interact with the timing of other medicines. Your clinician knows your full medicine list and can tell you whether anything changes on a fast day.
The rav conversation comes second
Bring your clinician's answer to your rav. Your rav knows your community's practice and can apply the medical facts to the religious question. The rav will want to know whether your clinician says fasting poses a medical risk, what the warning signs are, and whether your medicines can be taken on the fast day.
Your rav may rule that you are exempt from fasting because your life is in danger. Your rav may rule that you can fast with your medicines. Your rav may rule that you can fast with conditions, such as breaking the fast if a warning sign appears. Your rav may rule that you should not fast. The ruling belongs to your rav, not to your clinician and not to you alone.
Bring the written answer from your clinician so your rav can see the exact words. Bring the list of warning signs. Bring the list of your medicines and whether they need water. Your rav will apply the halachic sources to your specific situation.
What Peninei Halakha says about medicine on a fast day
Peninei Halakha states that sick people who need to take medicine regularly, such as a person who suffers from a chronic disease, must continue taking their medicine even on a fast day [1]. The source does not say you may take medicine; it says you must. If your clinician says you need the medicine, you take it.
Peninei Halakha states that if possible one should swallow it without water; that almost no medicine does any harm to those who take it without water; and that one who cannot swallow pills without water should add something bitter to the water until it becomes undrinkable and use it to swallow the pill [1]. This is what the literature says. Whether this applies to your specific medicines is a question for your pharmacist and your rav.
The fast-day tiers and what they mean for the sick
The rules differ between Yom Kippur and other fast days. On Yom Kippur, a Biblical fast, only people whose lives may be in danger if they fast are exempt [1]. On the other fasts, which were instituted by the Rabbis, anyone who is sick is exempt from fasting even if the condition is not life-threatening [1].
Peninei Halakha records the view that Tisha B'Av differs from the minor fasts, with only someone who is actually sick or liable to become sick because of the fast exempt on Tisha B'Av while even someone in great pain is exempt from the minor fasts [1]. Peninei Halakha also records that many poskim do not make such a distinction [1]. Your rav will know how your community treats this.
The minor fasts are the Fast of Gedaliah, the Tenth of Tevet, the Fast of Esther, and the Seventeenth of Tammuz. On these fasts, Peninei Halakha states that anyone who is sick is exempt from fasting even if the condition is not life-threatening, and that in general people whose pain or weakness precludes them from continuing their regular routine of life, forcing them to lie down, are considered sick [1].
Planning your medicine list with your pharmacist
Three weeks before the fast, sit down with your pharmacist and write out your complete medicine list. Include the name of each medicine, the strength, how often you take it, and whether it needs water to swallow. Include over-the-counter medicines, inhalers, and medicines you take only sometimes.
Ask your pharmacist which medicines can be swallowed without water and which ones cannot. Ask whether any medicine should be taken at a different time on a fast day. Ask whether any medicine interacts with fasting or with the timing of other medicines. Write down the answers.
Bring this list to your clinician when you have the fast-day conversation. Bring it to your rav. Keep a copy for yourself on the fast day.
Preparing for the fast day itself
The Yom Kippur medication guide covers what to do on the fast day itself. The medication on fast days guide covers the general principles. The guides hub collects all the fasting and medication articles in one place.
Preparation checklist
Three weeks before the fast
- Check the exact date on Hebcal: Yom Kippur begins at sundown on Sunday, September 20, 2026, and ends at nightfall on Monday, September 21, 2026 [2].
- Book a conversation with your clinician and tell them you are preparing to fast on a specific date.
- Sit down with your pharmacist and write out your complete medicine list, including the name, strength, and how often you take each one.
- Ask your pharmacist which medicines can be swallowed without water and which ones cannot.
One week before the fast
- Have the conversation with your clinician. Ask whether your body and your condition can go without food and water from sundown to nightfall. Ask what warning signs mean you should break the fast immediately. Ask whether any medicine should be taken differently on a fast day. Write down the answers.
- Bring your clinician's written answer and your medicine list to your rav.
- Ask your rav whether you are exempt from fasting, whether you can fast with your medicines, or whether you should not fast.
The day before the fast
- Recheck the fast date against Hebcal to confirm the sundown and nightfall times.
- Lay out all your medicines and the written instructions from your clinician and your rav.
- Set a reminder on your phone for the warning signs your clinician named.
- Eat and drink normally before sundown.
What to do next
- Open Hebcal and confirm that Yom Kippur begins at sundown on Sunday, September 20, 2026 [2].
- Call your clinician this week and book a conversation for at least 3 weeks before the fast.
- Meet with your pharmacist and write down your complete medicine list with the name, strength, and how often you take each one.
- Ask your pharmacist which medicines can be swallowed without water and which ones need water.
- Before your clinician appointment, write down the specific question: can my body and my condition go without food and water from sundown to nightfall?
- At the clinician appointment, ask what warning signs mean you should break the fast immediately and write down the exact signs.
- Ask your clinician whether any of your medicines should be taken differently on a fast day.
- Bring your clinician's written answer, your medicine list, and the warning signs to your rav.
- Ask your rav whether you are exempt from fasting, whether you can fast with your medicines, or whether you should not fast, and get the ruling in writing.
Sources
- Peninei Halakha, the infirm are exempt from fasting, accessed 2026-08-09, https://ph.yhb.org.il/en/05-07-07/
- Hebcal, Yom Kippur 2026, accessed 2026-08-09, https://www.hebcal.com/holidays/yom-kippur-2026