Caffeine is a regular part of life for many. But some people may need to limit or cut out caffeine. It's not a harmless substance, and it can affect your health. So it's helpful to know how much you're consuming and when to cut back.

Caffeine affects the nervous system and can make you feel more awake and alert. But it can also make you feel jittery. It increases your heart rate and blood pressure. It can cause stomach pain and diarrhea. It makes you urinate more and can lead to dehydration. And it can make it harder to sleep.

You may need to be careful with caffeine if you have any of these:

• Acid reflux (GERD)
• Anxiety
• Irregular heartbeats or rhythm (arrythmias)
• High blood pressure
• Migraines
• Trouble sleeping (insomnia)

People who are pregnant need to watch how much caffeine they have. Caffeine goes into the bloodstream and passes through the placenta to a baby in the uterus. Expert groups advise having no more than 200 mg of caffeine per day.

If you're breastfeeding, a small amount of caffeine goes into breast milk. The CDC advises staying below 300 mg of caffeine a day.

Make sure to read labels to see if a product has caffeine. Caffeine is in many things, such as:

• Black teas
• Chocolate (cacao)
• Coffees
• Cola (diet and regular)
• Energy drinks
• Energy snacks
• Some electrolyte drinks or powders
• Green teas
• Guarana
• Ice cream and yogurt flavored with coffee
• Some over-the-counter pain medicines
• Yerba mate

The amount of caffeine that's okay for each person varies a lot. The FDA says that a healthy adult can safely take in up to 400 mg a day. But some people are very sensitive to caffeine and need to have less or none. Think about how caffeine makes you feel. No safe limits have been set for children, and expert groups recommend that children and adolescents not consume caffeine. Having too much caffeine can cause:

• Anxiety
• Fast heart rate
• Headache
• Jittery feeling
• Stomach pain or nausea
• Trouble sleeping

Ask your doctor about what amount of caffeine is safe for you.

Below are some caffeine basics. Make sure to read labels. Caffeine amounts can vary greatly in every type of drink or food. But there are no laws about listing caffeine on labels, so a product may have some and not state it. Look on manufacturer websites or contact companies if products don't say how much caffeine they have.

No. Decaf coffee still has some caffeine in it. It's just a much smaller amount. Read package labels or search online databases to find out the amount your drink or food has.

Need to cut back? Do it slowly. This means reducing your caffeine day by day. Your body gets used to caffeine if you have it often. If you stop your caffeine habits suddenly, you may have withdrawal symptoms. These can include:

• Headaches
• Irritable or depressed moods
• Tiredness
• Trouble thinking

To safely cut back or stop caffeine, follow these steps:

1. Decide how much caffeine you want to have each day. You may want a bit less, a lot less, or none. Figure out how many caffeine drinks or foods that would be.

2. Write down how many caffeine drinks or foods you currently have each day.

3. Make a plan to replace some of those with a decaf version. Don't replace all of them at once. For instance, if you have 4 cups of coffee, make 2 of those decaf. Decaf has a small amount of caffeine.

4. Over the next 1 to 2 weeks, replace more with decaf or noncaffeine drinks or foods. Do this until you reach the amount of caffeine you plan to have each day.

Cutting out caffeine doesn't mean you're stuck with just water. There are lots of other choices. Try some of these:

• Carob
• Chicory root coffee
• Ginseng
• Herbal teas
• Milk with spices (golden milk)
• Mushroom coffee
• Rooibos tea

If you've stopped caffeine, you may notice that, after a few weeks, you have steadier energy during the day. You may sleep better at night. Or you may miss the effects of caffeine. This is common, and you're not alone. If you still feel tired after a few weeks, you may want to ask your doctor for help. Your sleep, diet, and stress levels can affect how tired you feel.