| Obsessive Compulsive | See Obsessive-Compulsive Disorder. |
| Obsessive-Compulsive | See Obsessive-Compulsive Disorder. |
| Obsessive-Compulsive Disorder | |
| Occiput | Hind-most region on the top of the head. |
| Occult Blood | |
| OCD | See Obsessive-Compulsive Disorder. |
| Oestrogen | See Estrogen. |
| Oliguria | |
| Oliguric | See Oliguria. |
| Oncologist | |
| Oncologists | See Oncologist. |
| Oncology | |
| Ophthalmia | Severe eye inflammation, including conjunctivitis, iritis, severe hay fever, etc. |
| Opthalmalgia | Very simply, eye pain. |
| Opthalmia | See Ophthalmia. |
| Optical Prescription | The units used to represent the amount of correction needed in order to normalize vision for distance are called 'diopters'. The more nearsighted or farsighted you are, the higher your prescription is in diopters. Your prescription is usually written as three numbers, for example:
OD -4.25 -1.75 X 180
OS -5.50 -1.25 X 175
+2.25 Add OU
OD (referring to the Latin "Ocular Dexter") stands for right eye, and OS ("Ocular Sinister") is for the left eye. The first number (-4.25 and -5.50 in this example) is the degree of spherical nearsightedness or farsightedness. The sign identifies whether you are nearsighted (minus sign) or farsighted (plus sign). The second number (-1.75 and -1.25) is the degree of astigmatism. The number can be written either with a + sign or a - sign. The last and 3rd number (180 and 175) is the axis, or the direction of your astigmatism. An axis of 180 degrees, for example, means the astigmatism is horizontal. Therefore, this prescription means that the patient is moderately nearsighted, with a moderate degree of astigmatism in a horizontal direction. The "add" at the bottom of the prescription is for the reading part of a bifocal glass. It might be unusual for anyone under the age of 40 to need this. Some people only have one number written for each eye. This is when there is no astigmatism. |
| Oral Zinc Test | See Zinc Taste Test. |
| Orchitis | |
| Ornithine | |
| Oropharynx | |
| Orotate | An oratic acid salt (nucleic acid); an effective molecule for transporting minerals through cellular membranes. Functions as an essential part of every living cell. |
| Osgood-Schlatter Disease | |
| Osmotic Laxative | |
| Osmotic Laxatives | See Osmotic Laxative. |
| Osteoarthritic | See Osteoarthritis. |
| Osteoarthritis | |
| Osteoblast | |
| Osteoblastic | See Osteoblast. |
| Osteoblasts | See Osteoblast. |
| Osteochondritis | Inflammation of a bone and its cartilage. |
| Osteochondrosis | |
| Osteopath | See Osteopathy. |
| Osteopathic | See Osteopathy. |
| Osteopaths | See Osteopath. |
| Osteopathy | |
| Osteoporosis | |
| OTC | See Over-The-Counter. |
| Otitis Externa | Also called Swimmer’s Ear, this is an infection of the outer ear canal caused by either fungus or bacteria. Water that remains trapped in the ear canal (when swimming, for example) can provide a breeding ground for these bacteria and fungi. Symptoms include redness of the outer ear; itching in the ear; pain, especially when touching or wiggling the earlobe; drainage from the ear; swollen glands in the neck; a swollen ear canal; hearing loss. |
| Otitis Media | |
| Ounce | Approximately 28 grams. |
| Ounces | See Ounce. |
| Ovarian Cyst | See Ovarian Cysts. |
| Ovarian Cysts | |
| Ovaries | See Ovary. |
| Ovary | |
| Over The Counter | See Over-The-Counter. |
| Over-The-Counter | A drug or medication that can legally be bought without a doctor's prescription being required. |
| Oxalic Acid | |
| Oxytocin | |
| Oxyuriasis | See Pinworms. |
| Oxyurid | Pin worm. |
| oz | See Ounce. |
