QuestionSBA
QuestionChoice
Androgen testing in hair loss is mainly indicated when virilising features are noted such as hirsutism, acne or irregular menses, which are not present.
10015817
b
Androgen levels
QuestionChoice
These are less likely to be useful in investigating hair loss.
10015819
d
Vitamin D levels
QuestionChoice
Thyroid disorders and iron deficiency may both cause alopecia and hair loss, and would also be reasonable first-line investigations.
10015816
a
Thyroid function tests and ferritin
QuestionChoice
These are less likely to be useful in investigating hair loss.
10015820
e
B12 levels
QuestionChoice
Discoid lupus and other causes of scarring alopecia may be investigated with an ANA and other blood tests, however the scenario describes the patient being otherwise well with no obvious skin lesions.
10015818
c
Autoimmune panel
QuestionComment
would hair thinning around the scalp not fit with male pattern baldness which would indicate high androgen levels?
38632
User
subscriber
Dorsal Monoclonal
QuestionComment
would thyroid disorder present with only hair loss?
44200
User
subscriber
Chronic Nightshift
QuestionComment
So it says only do androgen testing if there's other symptoms present, but it's ok to do thyroid testing when there's no other symptoms present?? Thyroid disease would have so many other signs IRL!!! Dumb rationale in the answers here.
45691
User
subscriber
Amnesia Rhinoplasty
QuestionComment
why is this not alopecia areata?
53285
User
subscriber
Uzi
QuestionComment
wouldnt she have had to had other features eg thryoid symptoms or tiredness and then you check TFTs and ferritin - said she is otherwise well ?
59697
User
subscriber
Hypertension Kinase
QuestionComment
why not PCOS? surely more likely
60228
User
subscriber
Sydney Sweeney
Concept
Chapter
# Summary

Hypothyroidism, a prevalent endocrine disorder, arises due to the inadequate production of thyroid hormones, critical for metabolism and energy utilisation. Patients often present with a spectrum of signs and symptoms affecting various body systems. These encompass peripheral features like dry skin and brittle hair, head and neck manifestations such as macroglossia and a puffy face, cardiac indicators like bradycardia and cardiomegaly, and neurological deficits, including carpal tunnel syndrome and cerebellar ataxia. An assortment of causes underlies this condition, including autoimmune, iatrogenic, congenital, and iodine-related factors. Diagnosis hinges on comprehensive investigations aimed at identifying the underlying etiology, and management primarily revolves around hormone replacement therapy, with levothyroxine. Ongoing monitoring and management considerations are crucial to optimize treatment outcomes.


# Definition



Hypothyroidism is an endocrine disorder characterized by an insufficient production of thyroid hormones, which are crucial for metabolism and energy utilization in the body. 


# Epidemiology



Hypothyroidism exhibits a higher prevalence among females and escalates with age. Globally, it ranks as one of the most common endocrine disorders, with variations in its etiology across regions. While iodine deficiency remains a prominent cause worldwide, Hashimoto's thyroiditis predominates in the UK.



# Aetiology


The aetiology of hypothyroidism can be categorized into:

- Autoimmune causes: Hashimoto's thyroiditis, Atrophic thyroiditis and Autoimmune polyendocrine syndromes.
- Iatrogenic causes: Surgical removal of the thyroid, Radioablation, and Radiation therapy.
- Congenital causes: Thyroid aplasia and Pendred syndrome (defect in thyroxine synthesis).
- Iodine deficiency/excess related causes: Infiltrative disorders, Sarcoidosis and Haemochromatosis.


# Signs and Symptoms



The signs and symptoms of hypothyroidism cover a wide range and can be categorised under:

- Peripheral Features: Dry, thick skin, Brittle hair, Scanty secondary sexual hair.
	- Queen Anne's sign - loss of outer 1/3 of eyebrows 
- Cold intolerance, may result in wearing additional layers of clothing
- Head and Neck Features: Macroglossia, puffy face, goitre (depending on cause).
- Cardiac Features: bradycardia, cardiomegaly.
- Neurological Features: Carpal tunnel syndrome, slow relaxing reflexes, cerebellar ataxia, peripheral neuropathy, difficulty concentrating
- Joint pain
- Menorrhagia


# Differential Diagnosis



Given the wide range of symptoms, the differential diagnosis for hypothyroidism is broad and may include:

- Iron deficiency anaemia: fatigue, weakness, pallor, shortness of breath.
- Chronic fatigue syndrome: persistent fatigue, unrefreshing sleep, cognitive impairment.
- Depression: persistent low mood, lack of interest, feelings of guilt, sleep and appetite changes.

# Investigations


Investigations are aimed at determining the underlying cause of hypothyroidism:

- First line investigations would include thyroid function tests, which would show a low T3/4 and raised TSH.
- Antibody testing (Anti-TPO, Anti-thyroglobulin, Anti-TSH receptor) is used to identify autoimmune causes.
- Imaging and biopsy may be used to identify congenital and infiltrative causes.
- Iodine levels can be assessed to determine whether deficiency or excess is contributing to hypothyroidism.

# Management

* The primary therapeutic strategy for hypothyroidism revolves around hormone replacement therapy, with levothyroxine as the first-line treatment. 
* Review the patient and recheck TSH levels every 3 months after initiation of LT4 therapy and adjust the dose according to symptoms and TFT results. Once the TSH level is stable (2 similar measurements within the reference range 3 months apart), check TSH annually
	* During pregnancy, the dose of levothyroxine is usually increased by 25-50mcg due to increased metabolic demands
* Compliance with medication and lifestyle recommendations is crucial. 
* This management approach aids in averting complications such as osteoporosis and cardiac arrhythmias associated with untreated or poorly managed hypothyroidism.



# NICE Guidelines


[Click here for NICE CKS on hypothyroidism](https://cks.nice.org.uk/topics/hypothyroidism/).
645
672
Hypothyroidism
Topic
5
Endocrinology
Video
Concept
672
Hypothyroidism
193
1egke2Q
images/videos/endocrinology.png
Hypothyroidism
Video
Concept
672
Hypothyroidism
313
2sWRMn1
images/videos/endocrinology.png
Quesmed Tutorial: Endocrinology
Condition
341
Hypothyroidism
UkmlaTopic
10
Endocrine and metabolic
Condition
342
Hypothyroidism
UkmlaTopic
12
General practice and primary healthcare
15707
Investigate thyroid function and iron levels in women with unexplained hair loss to rule out hypothyroidism and anaemia as possible causes.
A 31-year-old woman comes to her GP surgery worried about losing her hair. She describes hair thinning across her scalp for 3 months. Her only past medical history is menorrhagia.

Which investigations are most likely to reveal the diagnosis?
a