Information for Patients
What is hypothyroidism?
Hypothyroidism, or underactive thyroid, happens when your thyroid gland doesn't make enough thyroid hormones to meet your body's needs.
Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods. Without enough thyroid hormones, many of your body's functions slow down. But there are treatments that can help.
What causes hypothyroidism?
Hypothyroidism has several causes. They include:
- Hashimoto's disease, an autoimmune disorder where your immune system attacks your thyroid. This is the most common cause.
- Thyroiditis, inflammation of the thyroid
- Congenital hypothyroidism, hypothyroidism that is present at birth
- Surgical removal of part or all of the thyroid
- Radiation treatment of the thyroid
- Certain medicines
- In rare cases, a pituitary disease or too much or too little iodine in your diet
Who is at risk for hypothyroidism?
You are at higher risk for hypothyroidism if you:
- Are a woman
- Are older than age 60
- Have had a thyroid problem before, such as a goiter
- Have had surgery to correct a thyroid problem
- Have received radiation treatment to the thyroid, neck, or chest
- Have a family history of thyroid disease
- Were pregnant or had a baby in the past 6 months
- Have Turner syndrome, a genetic disorder that affects females
- Have pernicious anemia, in which the body cannot make enough healthy red blood cells because it does not have enough vitamin B12
- Have Sjogren's syndrome, a disease that causes dry eyes and mouth
- Have type 1 diabetes
- Have rheumatoid arthritis, an autoimmune disease that affects the joints
- Have lupus, a chronic autoimmune disease
What are the symptoms of hypothyroidism?
The symptoms of hypothyroidism can vary from person to person and may include:
- Weight gain
- A puffy face
- Trouble tolerating cold
- Joint and muscle pain
- Dry skin
- Dry, thinning hair
- Decreased sweating
- Heavy or irregular menstrual periods
- Fertility problems in women
- Slowed heart rate
- Goiter, an enlarged thyroid that may cause your neck to look swollen. Sometimes it can cause trouble with breathing or swallowing.
Because hypothyroidism develops slowly, many people don't notice symptoms of the disease for months or even years.
What other problems can hypothyroidism cause?
Hypothyroidism can contribute to high cholesterol. In rare cases, untreated hypothyroidism can cause myxedema coma. This is a condition in which your body's functions slow down to the point that it becomes life-threatening.
During pregnancy, hypothyroidism can cause complications, such as premature birth, high blood pressure in pregnancy, and miscarriage. It can also slow the baby's growth and development.
How is hypothyroidism diagnosed?
Your health care provider may use many tools to make a diagnosis:
- A medical history, including asking about your symptoms
- A physical exam
- Thyroid tests, such as
- TSH, T3, T4, and thyroid antibody blood tests
- Imaging tests, such as a thyroid scan, ultrasound, or radioactive iodine uptake test. A radioactive iodine uptake test measures how much radioactive iodine your thyroid takes up from your blood after you swallow a small amount of it.
What are the treatments for hypothyroidism?
The treatment for hypothyroidism is medicine to replace the hormone that your own thyroid can no longer make. About 6 to 8 weeks after you start taking the medicine, you will get a blood test to check your thyroid hormone level. Your health care provider will adjust your dose if needed. Each time your dose is adjusted, you'll have another blood test. Once you find the right dose, you will probably get a blood test in 6 months. After that, you will need the test once a year.
If you take your medicine according to the instructions, you usually should be able to control the hypothyroidism. You should never stop taking your medicine without talking with your health care provider first.
If you have Hashimoto's disease or other types of autoimmune thyroid disorders, you may be sensitive to harmful side effects from iodine. Talk to your health care provider about which foods, supplements, and medicines you need to avoid.
Women need more iodine when they are pregnant because the baby gets iodine from the mother's diet. If you are pregnant, talk with your health care provider about how much iodine you need.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
The ICD-9 and ICD-10 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.
Index of Diseases and Injuries Definitions
- And - The word "and" should be interpreted to mean either "and" or "or" when it appears in a title.
- Code also note - A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
- Code first - Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
- Type 1 Excludes Notes - A type 1 Excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- Type 2 Excludes Notes - A type 2 Excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- Includes Notes - This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- Inclusion terms - List of terms is included under some codes. These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
- NEC "Not elsewhere classifiable" - This abbreviation in the Alphabetic Index represents "other specified". When a specific code is not available for a condition, the Alphabetic Index directs the coder to the "other specified” code in the Tabular List.
- NOS "Not otherwise specified" - This abbreviation is the equivalent of unspecified.
- See - The "see" instruction following a main term in the Alphabetic Index indicates that another term should be referenced. It is necessary to go to the main term referenced with the "see" note to locate the correct code.
- See Also - A "see also" instruction following a main term in the Alphabetic Index instructs that there is another main term that may also be referenced that may provide additional Alphabetic Index entries that may be useful. It is not necessary to follow the "see also" note when the original main term provides the necessary code.
- 7th Characters - Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
- With - The word "with" should be interpreted to mean "associated with" or "due to" when it appears in a code title, the Alphabetic Index, or an instructional note in the Tabular List. The word "with" in the Alphabetic Index is sequenced immediately following the main term, not in alphabetical order.