Thyroid test

A T3 immunoassay test helps to determine whether the thyroid is functioning properly. It is primarily done to diagnose hyperthyroidism. T3 is also done to monitor the progress of a patient with a known thyroid disorder. T3 test is also sometimes conducted along with thyroid antibodies test to diagnose diseases such as Graves' disease, which is an autoimmune disorder that is the most common cause of hypothyroidism. Most of the T3 in the blood is attached to the thyroxine binding globulin. Only less than 1% of the T3 remains unattached. A T3 blood test is used to measure both the bound and the free Triiodothyronine. Increased or decreased T3 test result indicates that there is an imbalance between the body's requirement and supply of the hormone. If a patient is being treated with anti-thyroid medication for hyperthyroidism and the T3 is normal, then it is likely that the medication is controlling the condition. If the T3 is elevated, then the medication is not sufficient and the patient may be experiencing symptoms associated with hyperthyroidism. The normal test value for T3 is 100 to 200 ng/dL (nanograms per deciliter).

The T4 immunoassay test helps measure the amount of Thyroxine or T4 in the blood. A T4 immunoassay test is primarily done in response to an abnormal TSH result. Sometimes T4 is done along with TSH blood test. Thyroid hormone screening is commonly performed in newborns in the US as part of newborn screening programs for congenital hypothyroidism which may cause mental retardation if left untreated. False positive results can occur when testing a newborn for congenital hypothyroidism. Therefore normally the test is repeated a few days after initial testing. If the results continue to be abnormal, then additional testing is done. The normal range of a T4 test for an adult is 5 - 11 ug/dL (nanograms per deciliter).

There are other thyroid tests that indicate a malfunction. One such test is the 'Thyroid antibodies' test. This test is used to measure the presence of antibodies against thyroid tissue. Antibodies mean that the person has autoimmune disease such as Hashimoto's Thyroiditis or Graves' disease ( a condition characterized by an enlarged thyroid gland, weight loss without loss of appetite, sweating, heart palpitations, nervousness and inability to tolerate heat).

Thyroxine-binding globulin (TBG) is another thyroid test which detects the TBG which is an important protein in the blood that carries the thyroid hormones T3 and T4. This is a rare test and not done very commonly. Other diagnostic tests that are used to investigate problems with thyroid gland are the thyroid scan, thyroid ultrasound and thyroid biopsy.

Nocturia

When deep slumber at night is regularly disrupted by an urgent feeling of urination, it is a condition called nocturia. It is common in older adults, both men and women, usually in the age group of 55 and 84 years. Nocturia is different from enuresis or bed-wetting wherein the person does not wake up from sleep but involuntarily empties the bladder. Nocturia affected person experiences sleep loss due to an urgent need to urinate. Mild nocturia is characterized by a need to urinate two to three times and in severe cases it can be anywhere between five to six times on a particular night, occasionally or daily.

Nocturia types and causes

Besides the normal aging process, nocturia is also linked to other causes. In women, besides age, childbirth or pelvic organ prolapse and menopause are often contributing factors to nocturia.

Nocturnal Polyuria

There is an overproduction of urine at night. In a 24-hour cycle the urine volume may be greater than 40 ml/kg or if the volume of urine passed at night exceeds one-third of the total daily urine output. The main feature of nocturnal polyuria is that more urine is produced during sleep which in turn induces more nighttime urination.

All fluids or even certain foods like salads, vegetables, fruits, rice and pasta with high water content can cause nocturnal polyuria. Diuretics, cardiac glycosides, demeclocycline, lithium, methoxyflurane, phenytoin, propoxyphene and excessive Vitamin D medication can lead to frequent urination. Ankle swelling is another common cause of nocturnal polyuria. Congestive heart failure, venous stasis, hypoalbuminemia or excessive salt intake are other causes for fluid retention.

Polyuria

In adults, the normal urine production is 1 to 2 liters. Polyuria is characterized by urine output that exceeds 2500 ml/24 hours during the day as well as at night. Polyuria is common in people with diabetes mellitus and diabetes insipidus. Other conditions causing polyuria are Polycystic kidney disease, Sickle cell disease, Pyelonephritis, Amyloidosis, Sjogren syndrome and Myeloma. Vascular disease, restless leg syndrome, thyroid disorder and congestive heart failure are some causes for increased urinary output at night by the kidneys. Polydispisia or excessive thirst that compels drinking lots of water can cause polyuria. The thirst center or hypothalamus is affected due to anxiety, stress or psychiatric illness and leads to excessive thirst. Intravenous saline drip excessively administered can lead to polyuria. Hypercalcemia and hypokalemia lead to abnormal levels of electrolytes that can result in excessive urination.

Inadequate bladder storage

The urinary bladder has the capacity to hold as much as 600 ml of urine. But the desire to urinate is experienced when the level reaches about 150 ml. There are various reasons and conditions that lead to inadequate bladder storage. Bladder obstruction, bladder infection or recurrent urinary tract infection, bladder inflammation, pain in the bladder, bladder cancer can reduce bladder storage capacity. Stroke and Parkinson's disease can also lead to reduction in its storage capacity thus inducing an urgent need to empty the bladder.

Mixed Nocturia

A combination of nocturnal polyuria with reduced bladder capacity is termed as mixed nocturia.

Diagnosis of Nocturia

Basic diagnostic procedure is to record the frequency, volume and timing both daytime and nighttime for a minimum of 1-3 days. Certain diagnostic tests like urine analysis, urine culture or an ultrasound are done. Accordingly, the treatment procedure is determined. Treatment options include making dietary changes, behavioral changes with a combination of medications.

Thyroglobulin test

The thyroid gland is a small gland, which is located at the lower front of the neck. The thyroid gland takes thyroglobulin, a protein found within itself to make thyroid hormones namely, thyroxine and Triiodothyronine. In order to measure the amount of thyroglobulin in the blood, thyroglobulin test is done. The blood sample of the concerned individual is taken for conducting the thyroglobulin test. A needle is inserted into the veins in the arm to collect blood.

A thyroglobulin test is ordered under different circumstances. Thyroglobulin, as such, is used as a tumor marker. Thyroglobulin test is used to detect thyroid cancer. After detection of thyroid cancer and subsequent to treatment or surgery, in order to check and confirm recurrence, thyroglobulin test will be ordered. Thyroglobulin test may also be done on a periodical basis post thyroid cancer surgery to ensure that the tumor has not reoccurred or spread. The test is also recommended for patients who have symptoms of a thyroid disorder such as Grave's disease or thyroiditis. Thyroglobulin test is also ordered to check the efficacy of treatment in patients who have been prescribed anti-thyroid medications for some time.

Often several thyroglobulin levels are determined in a serial of samples to enable look at its change in concentration. The change provides more information than a single value. It is essential to have the serial thyroglobulin tests performed at the same laboratory as different test methods may produce different results in different diagnostic centers. Test results need to be discussed with your doctor. Based on these results, a doctor could follow up with a radioactive iodine scan or identify treatments to destroy remaining normal thyroid tissue or thyroid cancer if any.