Information for Patients
What is caffeine?
Caffeine is a bitter substance that occurs naturally in more than 60 plants including
- Coffee beans
- Tea leaves
- Kola nuts, which are used to flavor soft drink colas
- Cacao pods, which are used to make chocolate products
There is also synthetic (man-made) caffeine, which is added to some medicines, foods, and drinks. For example, some pain relievers, cold medicines, and over-the-counter medicines for alertness contain synthetic caffeine. So do energy drinks and "energy-boosting" gums and snacks.
Most people consume caffeine from drinks. The amounts of caffeine in different drinks can vary a lot, but it is generally
- An 8-ounce cup of coffee: 95-200 mg
- A 12-ounce can of cola: 35-45 mg
- An 8-ounce energy drink: 70-100 mg
- An 8-ounce cup of tea: 14-60 mg
What are caffeine's effects on the body?
Caffeine has many effects on your body's metabolism. It
- Stimulates your central nervous system, which can make you feel more awake and give you a boost of energy
- Is a diuretic, meaning that it helps your body get rid of extra salt and water by urinating more
- Increases the release of acid in your stomach, sometimes leading to an upset stomach or heartburn
- May interfere with the absorption of calcium in the body
- Increases your blood pressure
Within one hour of eating or drinking caffeine, it reaches its peak level in your blood. You may continue to feel the effects of caffeine for four to six hours.
What are the side effects from too much caffeine?
For most people, it is not harmful to consume up to 400mg of caffeine a day. If you do eat or drink too much caffeine, it can cause health problems, such as
- Restlessness and shakiness
- Rapid or abnormal heart rhythm
- Dependency, so you need to take more of it to get the same results
Some people are more sensitive to the effects of caffeine than others.
What are energy drinks, and why can they be a problem?
Energy drinks are beverages that have added caffeine. The amount of caffeine in energy drinks can vary widely, and sometimes the labels on the drinks do not give you the actual amount of caffeine in them. Energy drinks may also contain sugars, vitamins, herbs, and supplements.
Companies that make energy drinks claim that the drinks can increase alertness and improve physical and mental performance. This has helped make the drinks popular with American teens and young adults. There's limited data showing that energy drinks might temporarily improve alertness and physical endurance. There is not enough evidence to show that they enhance strength or power. But what we do know is that energy drinks can be dangerous because they have large amounts of caffeine. And since they have lots of sugar, they can contribute to weight gain and worsen diabetes.
Sometimes young people mix their energy drinks with alcohol. It is dangerous to combine alcohol and caffeine. Caffeine can interfere with your ability to recognize how drunk you are, which can lead you to drink more. This also makes you more likely to make bad decisions.
Who should avoid or limit caffeine?
You should check with your health care provider about whether you should limit or avoid caffeine if you
- Are pregnant, since caffeine passes through the placenta to your baby
- Are breastfeeding, since a small amount of caffeine that you consume is passed along to your baby
- Have sleep disorders, including insomnia
- Have migraines or other chronic headaches
- Have anxiety
- Have GERD or ulcers
- Have fast or irregular heart rhythms
- Have high blood pressure
- Take certain medicines or supplements, including stimulants, certain antibiotics, asthma medicines, and heart medicines. Check with your health care provider about whether there might be interactions between caffeine and any medicines and supplements that you take.
- Are a child or teen. Neither should have as much caffeine as adults. Children can be especially sensitive to the effects of caffeine.
What is caffeine withdrawal?
If you have been consuming caffeine on a regular basis and then suddenly stop, you may have caffeine withdrawal. Symptoms can include
- Difficulty concentrating
These symptoms usually go away after a couple of days.
- Caffeine in the diet (Medical Encyclopedia)
- Caffeine overdose (Medical Encyclopedia)
Medicines treat infectious diseases, prevent problems from chronic diseases, and ease pain. But medicines can also cause harmful reactions if not used correctly. Errors can happen in the hospital, at the health care provider's office, at the pharmacy, or at home. You can help prevent errors by
- Knowing your medicines. When you get a prescription, ask the name of the medicine and check to make sure that the pharmacy gave you the right medicine. Make sure that you understand how often you should take the medicine and how long you should take it.
- Keeping a list of medicines.
- Write down all of the medicines that you are taking, including the names of your medicines, how much you take, and when you take them. Make sure to include any over-the-counter medicines, vitamins, supplements, and herbs that you take.
- List the medicines that you are allergic to or that have caused you problems in the past.
- Take this list with you every time you see a health care provider.
- Reading medicine labels and following the directions. Don't just rely on your memory - read the medication label every time. Be especially careful when giving medicines to children.
- Asking questions. If you don't know the answers to these questions, ask your health care provider or pharmacist:
- Why am I taking this medicine?
- What are the common side effects?
- What should I do if I have side effects?
- When should I stop this medicine?
- Can I take this medicine with the other medicines and supplements on my list?
- Do I need to avoid certain foods or alcohol while taking this medicine?
Food and Drug Administration
- 6 Tips to Avoid Medication Mistakes (Food and Drug Administration)
- How and when to get rid of unused medicines (Medical Encyclopedia)
- Keeping your medications organized (Medical Encyclopedia)
- Medication safety during your hospital stay (Medical Encyclopedia)
- Medication safety: Filling your prescription (Medical Encyclopedia)
- Storing your medicines (Medical Encyclopedia)
- Taking medicine at home - create a routine (Medical Encyclopedia)
General Equivalence Map Definitions
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.
- Approximate Flag - The approximate flag is on, indicating that the relationship between the code in the source system and the code in the target system is an approximate equivalent.
- No Map Flag - The no map flag indicates that a code in the source system is not linked to any code in the target system.
- Combination Flag - The combination flag indicates that more than one code in the target system is required to satisfy the full equivalent meaning of a code in the source system.