For millions of people, the day does not truly begin until that first cup of coffee hits the table. Its aroma, warmth and caffeine boost can make mornings feel easier, but what does drinking coffee every morning actually do to your body?

The answer is a mixture of potential benefits and drawbacks.

The Good Side of Morning Coffee

Coffee can improve alertness, concentration and energy, thanks largely to caffeine, a stimulant that affects the central nervous system. Moderate amounts may help people feel more awake and mentally focused, especially during the morning hours.

Coffee is also rich in naturally occurring plant compounds, including polyphenols. Research has associated moderate coffee consumption with a lower risk of several chronic conditions, including type 2 diabetes, cardiovascular disease and certain liver-related illnesses. However, these findings largely show associations and do not prove that coffee alone prevents disease.

Recent cardiovascular guidance also indicates that moderate caffeine intake may be compatible with good heart health for many adults.

When Coffee Becomes a Problem

The same caffeine that provides an energy boost can cause trouble when consumed excessively.

Too much may lead to jitters, anxiety, headaches, a racing heartbeat and difficulty sleeping. Some people are much more sensitive to caffeine than others, meaning even one or two cups can produce uncomfortable effects.

Coffee may also irritate the stomach in sensitive individuals. And drinking it later in the day can interfere with sleep, creating a cycle in which poor sleep leads to even more caffeine the following morning.

What goes into your cup matters too. Coffee loaded with sugar, flavored syrups and heavy cream can quickly add significant calories and added sugar, reducing some of the advantages of plain coffee.

How Much Is Too Much?

For most healthy adults, the FDA says up to 400 milligrams of caffeine daily roughly two to three 12-ounce cups of coffee, depending on strength—is generally not associated with harmful effects. Pregnant people, those taking certain medications, and people with particular medical conditions may need lower limits.

The bottom line: your morning coffee does not have to be a guilty pleasure. Keep portions reasonable, limit added sugar, pay attention to how your body reacts, and avoid allowing caffeine to replace good sleep, hydration and a balanced breakfast.