WEBVTT

00:00:08.304 --> 00:00:11.485
The thyroid gland (glandula thyreoidea)

00:00:11.485 --> 00:00:14.333
is a hormone gland
in the larynx in the neck.

00:00:15.115 --> 00:00:20.000
It produces thyroid hormones
which contain iodine:

00:00:20.000 --> 00:00:22.323
triiodothyronine (T3)

00:00:22.323 --> 00:00:27.826
and tetraiodothyronine,
also known as thyroxine (T4).

00:00:27.826 --> 00:00:31.988
These hormones play an important part
in human metabolism

00:00:31.988 --> 00:00:36.917
and help to regulate
a number of bodily functions.

00:00:36.917 --> 00:00:40.259
In fetuses, newborns and children

00:00:40.259 --> 00:00:45.946
these thyroid hormones are essential
for growth and maturation of the body.

00:00:45.946 --> 00:00:49.063
If the thyroid gland stops working properly

00:00:49.063 --> 00:00:53.298
it may produce too many hormones
or not enough.

00:00:53.298 --> 00:00:55.688
Either type of disruption
to hormone production

00:00:55.688 --> 00:00:58.000
can cause numerous problems.

00:00:58.646 --> 00:01:01.556
If the thyroid gland
does not produce enough hormones

00:01:01.556 --> 00:01:06.392
this is referred to as hypothyroidism.

00:01:06.392 --> 00:01:10.517
Low levels of thyroid hormones
slow down metabolism

00:01:10.517 --> 00:01:12.595
which can cause, for example,

00:01:12.595 --> 00:01:13.821
listlessness,

00:01:13.821 --> 00:01:15.454
sensitivity to cold,

00:01:15.454 --> 00:01:18.071
weight gain or constipation

00:01:18.071 --> 00:01:20.529
or depression.

00:01:21.396 --> 00:01:26.307
Hypothyroidism (underactive thyroid)
is frequently caused

00:01:26.307 --> 00:01:29.001
by Hashimoto’s thyroiditis.

00:01:29.001 --> 00:01:33.892
This is an autoimmune disease
where the body’s defense system

00:01:33.892 --> 00:01:36.376
mistakenly attacks the cells
of the thyroid gland.

00:01:36.376 --> 00:01:40.196
This causes chronic inflammation
of the thyroid gland.

00:01:40.196 --> 00:01:44.728
Hypothyroidism
responds well to treatment with drugs

00:01:44.728 --> 00:01:49.924
containing the active ingredient
levothyroxine (L-thyroxine)

00:01:49.924 --> 00:01:54.036
which replaces
the body’s own hormone thyroxine (T4).

00:01:54.872 --> 00:01:58.704
The symptoms usually clear up completely
when treated.

00:01:58.704 --> 00:02:02.000
Depending on the cause,
treatment of hypothyroidism

00:02:02.000 --> 00:02:04.000
may be temporary or may be lifelong.

00:02:05.411 --> 00:02:07.837
If the thyroid gland produces
too many hormones

00:02:07.837 --> 00:02:13.329
this is referred to as
hyperthyroidism or overactive thyroid.

00:02:13.329 --> 00:02:19.517
Hyperthyroidism makes many bodily functions
work continuously “flat out”.

00:02:19.517 --> 00:02:21.237
It can be detected by symptoms such as

00:02:21.237 --> 00:02:26.435
weight loss, sweating, nervousness
or heart palpitations.

00:02:27.044 --> 00:02:31.157
This means that hyperthyroidism
also increases the risk

00:02:31.157 --> 00:02:33.677
of certain cardiovascular diseases.

00:02:34.279 --> 00:02:37.548
The commonest cause of hyperthyroidism

00:02:37.548 --> 00:02:41.013
is Basedow’s disease.

00:02:41.849 --> 00:02:46.118
This again is an autoimmune disease.

00:02:46.118 --> 00:02:49.931
However in this case the immune system
produces antibodies

00:02:49.931 --> 00:02:53.485
that activate the thyroid gland
and make it grow.

00:02:53.485 --> 00:02:56.240
This results in overproduction of hormones.

00:02:57.365 --> 00:02:59.681
Mild hyperthyroidism

00:02:59.681 --> 00:03:02.626
can occasionally clear up
even if untreated.

00:03:02.626 --> 00:03:05.518
In most cases, production of
excess hormones in the thyroid gland

00:03:05.518 --> 00:03:08.173
is initially slowed down
by administering tablets

00:03:08.173 --> 00:03:10.380
known as “thyreostatics”.

00:03:11.497 --> 00:03:13.071
Long-term use of thyreostatics

00:03:13.071 --> 00:03:20.024
can restore normal thyroid function
in people with Basedow’s disease.

00:03:20.024 --> 00:03:21.384
If this does not work

00:03:21.384 --> 00:03:25.751
parts or all of the gland
is surgically removed

00:03:25.751 --> 00:03:28.181
or treated with radioactive iodine.

00:03:28.181 --> 00:03:32.243
Radioactive iodine therapy involves
administering radioactive iodine

00:03:32.243 --> 00:03:34.321
which accumulates in the thyroid gland

00:03:34.321 --> 00:03:36.943
and destroys the overactive cells.

00:03:37.669 --> 00:03:42.313
If hyperthyroidism is not properly treated

00:03:42.313 --> 00:03:45.010
the people affected
may develop cardiovascular diseases

00:03:45.010 --> 00:03:47.431
such as atrial fibrillation.

00:03:47.431 --> 00:03:49.899
Over the long term
it may accelerate bone remodeling

00:03:49.899 --> 00:03:55.568
leading to osteoporosis (weak bones).

00:03:56.193 --> 00:03:58.618
A blood test can shed light

00:03:58.618 --> 00:04:01.938
on whether existing symptoms are caused
by a thyroid gland disorder

00:04:01.938 --> 00:04:04.654
or a precursor to such a disorder.

00:04:05.161 --> 00:04:07.017
In short:

00:04:07.017 --> 00:04:09.399
The thyroid gland is a hormone gland

00:04:09.399 --> 00:04:13.440
that regulates metabolism
and many bodily functions

00:04:13.440 --> 00:04:14.751
through its thyroid hormones.

00:04:14.751 --> 00:04:20.087
Hypothyroidism (underactive thyroid),
which shuts down the metabolism

00:04:20.087 --> 00:04:23.276
and is associated particularly
with fatigue and being overweight,

00:04:23.276 --> 00:04:24.868
is frequently caused

00:04:24.868 --> 00:04:27.821
by the autoimmune disease
Hashimoto’s thyroiditis.

00:04:27.821 --> 00:04:30.000
It can be treated with drugs

00:04:30.000 --> 00:04:33.034
to replace the missing thyroid hormone T4.

00:04:33.612 --> 00:04:36.000
Hyperthyroidism (overactive thyroid)

00:04:36.000 --> 00:04:39.288
is most commonly caused
by Basedow’s disease

00:04:39.288 --> 00:04:42.146
where the thyroid gland is enlarged
and permanently activated.

00:04:42.982 --> 00:04:46.267
People with hyperthyroidism sweat quickly,

00:04:46.267 --> 00:04:48.735
are nervous and have heart palpitations.

00:04:48.735 --> 00:04:51.970
If hyperthyroidism
does not clear up by itself

00:04:51.970 --> 00:04:55.212
tablets are prescribed
to slow down hormone production

00:04:55.212 --> 00:04:58.056
and return it to normal levels
in the long term.

00:04:58.056 --> 00:05:01.251
If this does not work
thyroid gland tissue must be removed

00:05:01.251 --> 00:05:05.132
or destroyed by radioactive iodine therapy.