All Tests

A red cell distribution width (RDW) test is a measurement of the range in the volume and size of your red blood cells (erythrocytes). Red blood cells move oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and stay healthy. If your red blood cells are larger than normal, it could indicate a medical problem.

Other names: RDW-SD (standard deviation) test, Erythrocyte Distribution Width

The goal of wildlife rehabilitation is to provide professional care to sick, injured, and orphaned wild animals so ultimately they can be returned to their natural habitat. Wild animals that sustain injuries or illnesses preventing them from living successfully in the wild usually are euthanized (have their suffering ended in a humane fashion). Occasionally, individual animals that have recovered from their injuries but are not able to survive in the wild are placed in educational facilities.

Wildlife rehabilitation is not an attempt to turn wild animals into pets. Patients are held in captivity only until able to live independently in the wild. Fear of humans is a necessary survival trait for wild animals and every effort is made to minimize human contact and prevent the taming of rehabilitation patients. Often wildlife rehabilitation is an elaborate and time-consuming process.

Wildlife rehabilitators work with veterinarians to assess injuries and diagnose a variety of illnesses. Due to the important differences between wild animals and domestic animals, rehabilitators need extensive knowledge about the species in care, including natural history, nutritional requirements, behavioral issues, and caging considerations. They also need to understand any dangers the animals may present to rehabilitators. Rehabilitators must also be able to administer basic first aid and physical therapy, and understand any dangers the animals may present to rehabilitators.

Almost all birds are protected by federal law; state laws protect most other kinds of wildlife. To work with mammals, reptiles, and amphibians, wildlife rehabilitators must be issued special permits from their state wildlife agencies. Before receiving these permits, individuals must meet various requirements such as specialized training, participation in mentorship programs, facility inspections, and written or oral exams. Rehabilitators who wish to care for birds also must get permits from the US Fish & Wildlife Service. Once they receive the permits, conscientious rehabilitators continue their education by attending conferences, seminars, and workshops, keeping up with published literature, and networking with others in the field. 



Because of their training, wildlife rehabilitators can help concerned people decide whether an animal truly needs help. Young birds and mammals should be returned to their families if at all possible; even well trained rehabilitators are not equivalent replacements for biological parents. Rehabilitators can provide instructions on how to reunite wildlife families, keeping the safety of the animals and the rescuers in mind, and they can suggest humane, long-term solutions when conflicts arise between humans and their wild neighbors. 


Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or trauma. Three common neuropsychological problems treatable with rehabilitation are attention deficit/hyperactivity disorder (ADHD), concussion, and spinal cord injury. Rehabilitation research and practices are a fertile area for clinical neuropsychologists and others.

Breaking out (eruption) of the skin. A rash can be caused by an underlying medical condition, hormonal cycles, allergies, or contact with irritating substances. Treatment depends on the underlying cause of the rash. Medically, a rash is referred to as an exanthem.

A breast rash describes redness and irritation of the skin on your breast. A breast rash can also be itchy, scaly, painful or blistered.

Other terms used to describe a breast rash include dermatitis and hives.

Razor burn can affect any person who shaves part of their body. If you’ve ever had a red rash after shaving, you were likely experiencing razor burn.

Restless legs syndrome (RLS) is a disorder of the part of the nervous system that causes an urge to move the legs. Because it usually interferes with sleep, it also is considered a sleep disorder.

Rabies is a viral illness spread via the saliva of an infected animal. This occurs usually through biting a human or another animal. Transmission can also occur through saliva touching an open wound or touching mucous membranes.

Reactive arthritis is a type of arthritis that an infection in the body can trigger. Most commonly, a sexually transmitted infection or bacterial infection in the intestines triggers development of reactive arthritis.It’s considered to be an autoimmune disease of the spondyloarthritis group. The arthritis often doesn’t develop until after the infection has been successfully treatedPeople with reactive arthritis often experience symptoms in the larger joints of the lower extremity. Reactive arthritis was previously known as Reiter’s syndrome, a triad of arthritis, eye inflammation (conjunctivitis), and urinary tract inflammation (urethritis).The condition was previously thought to be uncommon. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), men develop reactive arthritis more often than women, but the diagnosis is more difficult in women. The average age of onset is 30 years old. Men also tend to experience more severe joint pain than women.

The retina is the light-sensitive layer of tissue that lines the inside of the eye and sends visual messages through the optic nerve to the brain. When the retina detaches, it is lifted or pulled from its normal position. If not promptly treated, retinal detachment can cause permanent vision loss.In some cases there may be small areas of the retina that are torn. These areas, called retinal tears or retinal breaks, can lead to retinal detachment.

Yoga is a science, that is, it is a body of techniques that lead us to consciously connect with ourselves and with life, the experience of yoga. As yoga is a science, there is no dogma or belief system attached to it. Yoga simply tells us to do a certain practice and then to feel the effect of that practice, e.g. if we breath slowly in a relaxed manner we will slow our heart rate; if we focus the mind we will develop mental peace and deep insight.

Radiation is used in the treatment of cancer and comes with risks. Radiation enteritis is one of these risks. This condition is caused by the inflammation of your small and/or large intestine from radiation treatments in your stomach, sexual organs, or rectum. Radiation enteritis can cause the loss of both intestinal cells and tissue.There are two types of radiation enteritis: acute and chronic. Acute enteritis develops while you are getting radiation treatments. The condition will last until about eight weeks after your last radiation treatment. Chronic enteritis can cause symptoms that last for months to years after you complete your radiation treatment.

Radiation sickness is damage to your body caused by a large dose of radiation often received over a short period of time (acute). The amount of radiation absorbed by the body — the absorbed dose — determines how sick you'll be.Radiation sickness is also called acute radiation sickness, acute radiation syndrome or radiation poisoning. Common exposures to low-dose radiation, such as X-ray or CT examinations, don't cause radiation sickness.Although radiation sickness is serious and often fatal, it's rare. Since the atomic bombings of Hiroshima and Nagasaki, Japan, during World War II, most cases of radiation sickness have occurred after nuclear industrial accidents, such as the 1986 fire that damaged the nuclear power plant at Chernobyl, Ukraine.

Ramsay Hunt syndrome happens when shingles affects nerves in your face close to either one of your ears. Shingles affecting either ear is a condition caused by a virus called herpes zoster oticus. The general varicella-zoster virus also causes chicken pox, which is most common in children. If you’ve had chicken pox in your life, the virus can reactivate later in your life and cause shingles. Both shingles and chicken pox are most recognizable by a rash that appears in the affected area of the body. Unlike chicken pox, a shingles rash near the facial nerves by your ears can cause other complications, including facial paralysis and ear pain. When this happens, it’s called Ramsay Hunt syndrome. If you get a rash on your face and also start noticing symptoms such as facial muscle weakness, see your doctor as soon as you can. Early treatment can help make sure you don’t experience any complications from Ramsay Hunt syndrome.

Raynaud's (ray-NOHZ) disease causes some areas of your body — such as your fingers and toes — to feel numb and cold in response to cold temperatures or stress. In Raynaud's disease, smaller arteries that supply blood to your skin narrow, limiting blood circulation to affected areas (vasospasm). Women are more likely than men to have Raynaud's disease, also known as Raynaud or Raynaud's phenomenon or syndrome. It appears to be more common in people who live in colder climates. Treatment of Raynaud's disease depends on its severity and whether you have other health conditions. For most people, Raynaud's disease isn't disabling, but it can affect your quality of life.

When the occasional headache strikes, most of us take an over-the-counter (OTC) analgesic, such as acetaminophen, ibuprofen, aspirin, or a pain-relief medication containing caffeine. While OTC analgesics can help relieve headache pain they must be taken correctly — or they could actually make your headaches worse. The overuse or misuse of analgesic drugs — exceeding labeling instructions (such as taking the medications three or more days per week) or not following your healthcare provider’s advice — can cause you to "rebound" into another headache. When the pain reliever wears off, you may experience a withdrawal reaction, prompting you to take more medication. This only leads to another headache and the desire to take yet more medication. So the cycle continues until you start to suffer from chronic daily headaches, with more frequent headaches and more severe pain.

The rectum is the last several inches of the large intestine. It starts at the end of the final segment of your colon and ends when it reaches the short, narrow passage leading to the anus.Cancer inside the rectum (rectal cancer) and cancer inside the colon (colon cancer) are often referred to together as "colorectal cancer."While rectal and colon cancers are similar in many ways, their treatments are quite different. This is mainly because the rectum sits in a tight space, barely separated from other organs and structures in the pelvic cavity. As a result, complete surgical removal of rectal cancer is challenging and highly complex. Additional treatment is often needed before or after surgery — or both — to reduce the chance that the cancer will return.In the past, long-term survival was uncommon for people with rectal cancer, even after extensive treatment. Thanks to treatment advances over the past 30 years, rectal cancer can now, in many cases, be cured.

This patient education piece is designed to help improve patients’ understanding regarding rectal prolapse, specifically its presentation, evaluation and treatment. This information may also be useful to the friends, families, and caregivers of patients dealing with rectal prolapse. Treatment of this condition may often require surgery, and this patient education material is intended for patients with rectal prolapse who are considering or have been recommended surgery. It will address why surgery may have been recommended, what the various treatment options are, what it involves and how it may help patients.

A rectovaginal fistula (RVF) is an epithelial-lined tract between the rectum and vagina. For thousands of years, women simply tolerated the distressing symptoms generated by RVFs. Today, there is no need for such tolerance, because most RVFs can be surgically corrected via a number of approaches. [1] A small percentage, however, cannot be corrected, because of patient comorbidity or disease-related factors; in these cases, patients can be helped only by fecal diversion. [2]  This article discusses only acquired RVFs. Most RVFs are located at or just above the dentate line. Fistulas below the dentate line are not true RVFs but, rather, anovaginal fistulas; the treatment required for these differs from that required for RVFs.

Renal refers to anything related to the kidneys. Renal arteries carry blood from the heart to the kidneys. They branch directly from the aorta (the main artery coming off the heart) on either side and extend to each kidney. These arteries take a very large volume of blood to the kidneys to be filtered The heart pumps out approximately 5 liters of blood per minute, and about 1-1.5 liters (25%) of the total volume of blood pumped by the heart passes through the kidneys every minute.

Cancer starts when cells begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer? For information about the differences between childhood cancers and adult cancers, see Cancer in Children. Retinoblastoma is a cancer that starts in the retina, the very back part of the eye. It is the most common type of eye cancer in children. Rarely, children can have other kinds of eye cancer, such as medulloepithelioma, which is described briefly below, or melanoma.To understand retinoblastoma, it helps to know about the parts of the eye and how they work.

A retractile testicle is a testicle that may move back and forth between the scrotum and the groin. When the retractile testicle is residing in the groin, it might be easily guided by hand into its proper position in the scrotum — the bag of skin hanging behind the penis — during a physical exam.For most boys, the problem of a retractile testicle goes away sometime before or during puberty. The testicle moves to its correct location in the scrotum and stays there permanently.In fewer than 5 percent of cases, the retractile testicle remains in the groin and is no longer movable. When this happens, the condition is called an ascending testicle or an acquired undescended testicle.

Ejaculation is the ejection of semen out of the urethra (passageway inside the penis) when a man has an orgasm. Under normal circumstances, ejaculation propels semen forward through a man's urethra and out the tip of his penis. This is because a tiny sphincter (circular muscle) at the entrance to the bladder shuts the opening to the bladder and prevents semen from entering. Retrograde ejaculation is when the semen travels backwards into the bladder.

Rett syndrome is a rare, severe neurological disorder that affects mostly girls. It's usually discovered in the first two years of life, and a child's diagnosis with Rett syndrome can feel overwhelming. Although there's no cure, early identification and treatment may help girls and families who are affected by Rett syndrome. In the past, it was felt to be part of the Autism Spectrum Disorder. We now know that it is mostly genetically based.

A retrograde urethrogram is a routine radiologic procedure (most typically in males) used to image the integrity of the urethra. Hence a retrograde urethrogram is essential for diagnosis of urethral injury, or urethral stricture. The procedure involves the insertion of a Foley catheter into the distal urethra and minimally inflating it. This is followed by instillation of 30mL of water-soluble contrast and a plain radiograph is obtained; leakage of the contrast suggests urethral injury (usually secondary to pelvic trauma) and is an indication for surgical intervention.It is used when there is suspicion of urethral trauma, such as a history of trauma to the area followed by pain, inability to void urine, or the presence of blood at the urethral meatus, a scrotal hematoma, or free-floating prostate on rectal examination. If a urethral injury is suspected, a retrograde urethrogram should be performed before attempting to place a Foley catheter into the bladder. If there is a urethral disruption, a suprapubic catheter should be placed.

Sarcomas are cancers that develop from connective tissues in the body, such as muscles, fat, bones, the linings of joints, or blood vessels. There are many types of sarcomas. Rhabdomyosarcoma (RMS) is a cancer made up of cells that normally develop into skeletal muscles. The body has 3 main types of muscles.

Rheumatic fever is one of the complications associated with strep throat. It’s a relatively serious illness that can cause stroke, permanent damage to your heart, and death if it’s left untreated. The condition usually appears in children between the ages of 5 and 15, even though older children and adults have been known to contract the fever as well. It’s still common in places like sub-Saharan Africa, south central Asia, and certain populations in Australia and New Zealand.

Ringworm of the body is a fungal infection that develops on the top layer of your skin. It's characterized by a red circular rash with clearer skin in the middle. It may itch. Ringworm gets its name because of its appearance. No actual worm is involved. Also called tinea corporis, ringworm of the body is closely related to athlete's foot (tinea pedis), jock itch (tinea cruris) and ringworm of the scalp (tinea capitis). Ringworm often spreads by direct skin-to-skin contact with an infected person or animal. Mild ringworm often responds to antifungal medications that you apply to your skin. For more-severe infections, you may need to take antifungal pills for several weeks

Ringworm is a common skin disorder otherwise known as “tinea” or “dermatophytosis.” It is caused by a fungus that can live on skin, surfaces like locker room floors, and household items like towels, bedding, and clothes. While there are multiple forms of ringworm, the most common forms affect:

Roseola is a generally mild infection that usually affects children by age 2. It occasionally affects adults. Roseola is so common that most children have been infected with roseola by the time they enter kindergarten.Two common strains of herpes virus cause roseola. The condition typically causes several days of fever, followed by a rash.Some children develop only a very mild case of roseola and never show any clear indication of illness, while others experience the full range of signs and symptoms.Roseola typically isn't serious. Rarely, a very high fever can result in complications. Treatment of roseola includes bed rest, fluids and medications to reduce fever.

The rotator cuff is a group of muscles and tendons that surround the shoulder joint, keeping the head of your upper arm bone firmly within the shallow socket of the shoulder. A rotator cuff injury can cause a dull ache in the shoulder, which often worsens when you try to sleep on the involved side.Rotator cuff injuries occur most often in people who repeatedly perform overhead motions in their jobs or sports. Examples include painters, carpenters, and people who play baseball or tennis. The risk of rotator cuff injury also increases with age.Many people recover from rotator cuff disease with physical therapy exercises that improve flexibility and strength of the muscles surrounding the shoulder joint.Sometimes, rotator cuff tears may occur as a result of a single injury. In those circumstances, medical care should be provided as soon as possible. Extensive rotator cuff tears may require surgical repair, transfer of alternative tendons or joint replacement

Rubella is an acute, contagious viral infection. While rubella virus infection usually causes a mild fever and rash illness in children and adults, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or infants with congenital malformations, known as congenital rubella syndrome (CRS). The rubella virus is transmitted by airborne droplets when infected people sneeze or cough. Humans are the only known host.

Rumination syndrome, or Merycism, is a rare disorder that affects children and some adults. If your child has this condition, he or she will usually eat meals normally. But after about an hour or two, undigested food comes back up into his or her mouth from the esophagus. Your child will either rechew and reswallow the food, or spit it out. Typically this happens at every meal, day after day. Rumination is a reflex, not a conscious decision.

The spleen is an organ of the lymphatic system located on the left side of your stomach (abdomen) under the rib cage and diaphragm in a region that is referred to as the left upper quadrant. In humans the spleen is about the size of a fist and its primary roles are filtering the body’s blood and helps to fight infection. It also serves a role in storing and releasing certain types of immune cells that mediate tissue inflammation. [1]Rupturing a spleen describes an emergency situation in which your spleen has developed a disruption in its surface or blood supply. This is serious condition that can occur during a direct blow or trauma and without emergency treatment a ruptured spleen can cause life threatening internal bleeding. [2]