Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline. Blocking epinephrine causes a decrease in heart rate. Beta blockers are prescribed for tachycardia, glaucoma, high blood pressure and migraines.

Food manufacturers use a chemical process called fat hydrogenation to alter some of the monounsaturated and polyunsaturated fats in the products they make. Hydrogenated fats are what the food industry calls functional ingredients because they serve a purpose other than improved product quality or nutrition.

Pressure in the eyes is a condition that can have serious consequences if left unattended. When eye pressure increases, ocular nerves can become damaged, leading to a loss of peripheral vision as well as the possibility of contracting glaucoma.

Heart palpitations are irregular heartbeats that can cause your heart to race, flutter, pound, skip beats or briefly stop. A variety of factors can trigger heart palpatations, such as anxiety, stress, emotional distress, panic, heart problems, an overactive thyroid, nicotine, alcohol and caffeine.

Many diseases can cause extreme fatigue and weakness. According to MedlinePlus, a service of the U.S. National Library of Medicine and the National Institutes of Health, fatigue is a feeling of weariness, tiredness or a lack of energy, and fatigue is different from drowsiness.

A heart attack, also called a myocardial infarction, occurs when blood supply is cut off to the heart muscle. This can be caused by a blood clot in an artery, an arterial spasm, trauma or other events. Heart attacks are uncommon in young men, but they can occur.

Numbness in your arms or hands can be caused by a variety of nerve or blood vessel conditions. However, some are more serious than others. Arm and hand numbness can be a sign of a heart attack -- a life-threatening condition. Seek immediate medical attention if you suspect you are having a heart attack.

Congestive heart failure occurs when the heart fails to efficiently pump a sufficient amount of blood to the body's organs and tissues. As fluid pools in areas such as the lungs, they become congested. Also called CHF, congestive heart failure can come on suddenly or develop gradually.

Creatine phosphokinase, or CK or CPK, is an enzyme found in the brain, heart and skeletal muscles. A physician will commonly order a CPK test to determine whether a person has suffered a heart attack. There are different types of CPK and a physician uses this information to interpret abnormal results.

Most people are familiar with chest pain as a symptom of heart attack, but many think the telltale pain is confined to the left side. However, chest pain before a heart attack -- especially during strenuous exercise -- can occur anywhere in the chest.

The effects of a mild heart attack can be vague and transient, or permanent, resulting in more severe side effects. Many patients do not realize they have had a heart attack until they see a doctor for unresolved vague symptoms.

Even if an athlete is young and in peak physical shape, chest pain is a symptom that must always be taken seriously. While most bouts of chest pain in children and teens don't point to a serious heart problem, playing sports can aggravate existing, and sometimes fatal, heart conditions in teen athletes.