Methemoglobinemia is a blood disorder in which an abnormal amount of methemoglobin -- a form of hemoglobin -- is produced. Hemoglobin is the protein in red blood cells that carries and distributes oxygen to the body.
Caffeine. One 8-ounce cup of coffee has 95 milligrams of caffeine and a 1-ounce single shot of espresso has 64 milligrams. Consuming too much caffeine can make you restless, anxious and irritable. It can also interact with certain medications. Pregnant women may need to cut back on caffeine consumption.
A normal single cup of espresso is approximately 1 to 1.5 ounces of beverage, using approximately 7grams (1 tablespoon) of ground coffee and brewed over about 25 seconds (25 to 30 seconds). A normal double cup is between 2 and 3 ounces, using double the volume of coffee grounds (the same time - 25 to 30 seconds).