In the time leading up to surgery, your doctor might ask you to make small modifications to your lifestyle to help maximize your health and the success of the surgery. For example, your doctor might request that you stop taking vitamins and other supplements in the weeks before surgery.

The meniscus is a C-shaped piece of cartilage in the knee joint. This cartilage acts as a shock absorber for the knee joint during physical activity. MayoClinic.com states that any activity that causes a patient to forcefully twist or rotate the knee can lead to a torn meniscus.

Your kidneys are paired organs that keep your blood chemically clean and balanced. Each day, they sift water and waste from about 200 quarts of blood, according to the National Kidney and Urologic Diseases Information Clearinghouse.

A biopsy of the lungs is a diagnostic procedure during which a doctor removes a small portion of the lung tissue for further evaluation. Typically, this test is performed on patients with suspected lung disease or infection, such as lung cancer or pneumonia.

Tonsillectomy is an operation done to remove the tonsils. It is more commonly performed in children than in adults. Like any other surgery, tonsillectomy has risks. The problems that can arise particularly in adults include bleeding, pain, problems with anesthesia and delayed recovery.

The ulnar nerve is a nerve in the inner arm that runs from the armpit, past the inner elbow and into the fourth and fifth fingers.

General anesthesia -- a combination of medications that decrease brain activity and pain receptor response -- creates a lack of consciousness, immobility and loss of feeling.

Hemorrhoids are small bundles of veins in the anus that are considered part of normal anal anatomy. They can, however, become engorged with too much blood, usually due to straining during defecation. Symptoms such as bleeding, pain and itching then arise.

While anesthesia can be risky, it is a common practice used during a vast majority of surgical procedures. Anesthesia is a mix of pain relief and sensation administered before a surgery under the direction of an anesthesiologist.

The small intestine's function is to absorb ingested fluids and nutrients. There are many conditions whose treatment may require removal of a part of the small intestine, most notably cancers, Crohn’s disease, a blockade in an intestinal artery, a twisted loop of intestine, an obstruction, and some birth defects.

When you undergo a surgery that removes tissue — mastectomy or liposuction, for example — your body sometimes fills the space with fluid. This is called a seroma — an internal blister. A seroma is often painless and may not require treatment, but some types of inflammation may hamper your recovery and require draining.

Swelling, also called edema, is one of the most common symptoms experienced after a knee surgery. While it can contribute to discomfort and pain, swelling can also lead to more serious issues if left unchecked. Swelling can limit mobility of the knee and cause the surrounding muscles to be ineffective.