Does alcohol raise or lower blood sugar?
It can do both. Beer and cider raise it at first. But the bigger risk is a drop, which on insulin or some diabetes tablets can come next morning. One organ explains why.
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Does alcohol raise or lower blood sugar?
Both. Beer, ale and cider contain carbs, so Diabetes UK says they raise blood sugar at first. Spirits, dry wine and Prosecco do this less.
The alcohol itself pulls the other way. Drinking can make a hypo more likely. A hypo is low blood sugar, usually below 4 mmol/L.
| Drink | Effect on blood sugar | Diabetes UK tip |
|---|---|---|
| Beer, ale, cider | Has carbs, so raises it at first. | Check before and after drinking. |
| Spirits, dry wine, Prosecco | Less of a rise. | Use diet or sugar-free mixers. |
| Sweet wine, sherry, liqueurs | A lot of sugar. | Limit them. |
| Low-sugar beer and cider | Less sugar, but more alcohol. | Avoid them. |
| Low-alcohol wine | Often more sugar than normal wine. | Avoid, or keep to a glass or two. |
| Alcohol-free beer, wine, spirits | Still some sugar and carbs. | A good swap, but water is best. |
Source: Diabetes UK
There’s no “best” drink for people with diabetes. How far a drink moves your level depends on what and how much you drink, and what else you’re doing, like eating or dancing.
So learn your own pattern. Diabetes UK suggests checking before and after drinking. And eat when you drink: the NHS says don’t drink alcohol without eating.
Why can alcohol cause a hypo the next day?
The organ behind the drop is your liver. It stores sugar and releases it when your level drops. Diabetes UK says alcohol stands in the way of this.
Think of your liver as a safety net under your blood sugar. Alcohol weakens the net for a while.
Losing the net doesn’t mean you’ll fall. It does mean a fall is harder to recover from.
With diabetes, a night’s drinking can end in a hypo the next morning
- 1
You drink
Beer or cider may push your level up at first.
- 2
Your liver holds back
Alcohol stops it topping up your sugar as well when you drop.
- 3
The risk builds
It rises after you stop drinking and can last up to 24 hours.
- 4
It feels like a hangover
Hypo signs can look like a hangover, or like being drunk.
Source: Diabetes UK
The risk is highest if you use insulin or a sulphonylurea. That’s a type of diabetes tablet, such as gliclazide or glimepiride. Drinking a lot, or on an empty stomach, makes a hypo even more likely.
Feel rough the morning after? Check your blood sugar, don’t guess. Diabetes UK says to treat a hypo straight away, however awful you feel.
Does alcohol affect blood sugar if you don’t have diabetes?
Less clearly. The NHS says low blood sugar is rare without diabetes. Studies of a single bout of drinking in people without diabetes found falls, rises or no change.
The exception is drinking without eating. A 1998 review says alcohol-linked hypos typically happen in people who have been drinking but not eating, sometimes for days. That goes for people with or without diabetes.
Does alcohol cause diabetes? Diabetes UK says no, but drinking to excess can raise your risk of type 2.
That’s partly the calories. A large 250 ml glass of wine that’s 14% or stronger can be over 3 units and 200 calories.
Want to know where you stand? See normal blood sugar levels and prediabetes.
Can I drink alcohol if I have diabetes?
Yes, unless your diabetes team has told you not to. That’s the Diabetes UK advice. These habits cut the risk of a hypo.
Six ways to drink more safely with diabetes
- Eat when you drink, and don’t drink on an empty stomach.
- Drink no more than 14 units a week, spread over 3 days or more.
- Carry hypo treatment, like glucose tablets, and wear medical ID.
- Tell the people you’re with that you have diabetes and how to help with a hypo.
- Have water between drinks, and diet or sugar-free mixers with spirits.
- Check your blood sugar more often when drinking and regularly the next day, and have breakfast.
Sources: NHS; NHS: type 1; Diabetes UK
A unit is about a single 25 ml measure of spirits. More in alcohol units explained and lowest-calorie drinks.
Count carbs for insulin? Drinks have carbs, but you might not need your usual dose for them, because hypos are more likely. Ask your diabetes team before changing your insulin for alcohol.
Not sure if your medicine can cause hypos? Ask your healthcare team. Never stop or change a prescribed medicine without your prescriber.
Use a sensor? Ask your team about a low alarm, which Diabetes UK says can help you act quickly if you go low after drinking. See glucose monitors.
What to do if your blood sugar drops after drinking
- Below 4 mmol/LHypo. Treat it now.
- 4 up to 7 mmol/LNot low. Signs of a hypo? Treat it anyway.
- Above 7 mmol/LNHS: high on waking or before food.
Sources: NHS: low blood sugar; NHS: high blood sugar; Diabetes UK
Signs of a hypo can include:
- feeling hungry, dizzy, anxious or irritable
- sweating, shaking or tingling lips
- a pounding or fluttering heart
- feeling tired or weak
- blurred vision or other changes in your vision
- feeling confused
Have diabetes and you’re below 4, or have signs? Have something sugary now. Try a small glass of fruit juice or sugary fizzy drink, 5 glucose tablets, 4 large jelly babies or 2 tubes of glucose gel.
Check again after 10 to 15 minutes. Still below 4? Have more, and check again after 10 minutes.
Once you feel better and you’re above 4, eat something that lasts longer. Try some biscuits, a sandwich or your next meal if it’s due.
Over 7 on waking is high on the NHS guide. Your own levels may differ, so check with your care team. See also diabetic blood sugar levels.
When to speak to a GP
Call 999 if someone may have very low blood sugar and isn’t responding normally or is unconscious, and they’ve been drinking alcohol. Call too if there’s no glucagon injection (an emergency injection that raises blood sugar). Or if you don’t know how to use it, or one hasn’t worked within 10 minutes.
Call 999 or go to A&E if you think you have high blood sugar and you’re feeling sick, being sick or have stomach pain. The same goes if you’re breathing or your heart is beating faster than usual, or you feel drowsy or confused. Or if your breath smells fruity (like pear drops), or you have high ketones in your blood or pee.
If they’re unconscious, don’t give them food or drink. Put them in the recovery position. See a GP if:
- You have diabetes and get hypos often, or you’ve had severe hypos or hypos at night.
- You have diabetes and don’t always notice when your blood sugar is low.
- You don’t have diabetes and get signs of low blood sugar, such as shaking, sweating, a fast heartbeat and feeling confused.
- You haven’t been diagnosed with diabetes and feel very thirsty, pee a lot, feel weak or tired, have blurred vision or are losing weight. These are signs of high blood sugar.
If you have diabetes, your diabetes care team can help too. Thinking of switching to alcohol-free? See alcohol-free beer.