A hormone is a chemical substance produced by endocrine glands or certain tissues in the body. It is released into the bloodstream and travels to target organs, acting as a “messenger” between cells. Hormones help regulate and coordinate various body systems to function in harmony.
Functions and Importance of Hormones
Hormones act as messengers, transmitting signals from one cell to another. They stimulate growth, regulate immune responses, and control metabolic processes such as energy use, water balance, blood pressure, body temperature, and blood sugar levels. Hormones also influence mood and daily behaviors.
Where Hormones Are Produced
- Major Endocrine Glands: Hormones are produced by the pituitary gland, thyroid gland, adrenal glands, ovaries, testes, pancreas, and more.
- Minor Endocrine Glands / Localized Secretions: Some hormones are produced within specific organs (e.g., the intestines), exerting localized effects.
- Tissues: Fat, muscles, and skin can produce hormone-like substances that play important roles in various body systems.
- Neurons: Certain nerve cells produce neurotransmitters that act like hormones, influencing target organs.
Causes of Hormonal Imbalance
Hormonal imbalance can be caused by various factors, including:
- Inadequate rest, chronic stress, poor nutrition, or excessive energy expenditure.
- Age-related hormonal changes, especially after the age of 30 when production of some hormones declines.
- In women, fluctuations occur with menstrual cycles, pregnancy, breastfeeding, and menopause.
- In men, testosterone levels may gradually decrease with age, often accompanied by reduced muscle mass and increased body fat.
Because hormones regulate essential bodily systems, imbalances often have a direct impact on health.
Signs That May Indicate Hormonal Imbalance
- Low energy levels or easy fatigue
- Mood swings and poor sleep quality
- Weight or body composition changes (loss of muscle, increased fat)
- Skin and hair changes, hair loss, or acne
- Irregular menstruation or worsened PMS symptoms
- Decreased sexual function or libido changes
- Weakened immune system, frequent illness, or slower recovery
Types of Hormones in the Body
- Peptide Hormones: e.g., Insulin, Growth Hormone
- Steroid Hormones: e.g., Testosterone, Cortisol
- Amine Hormones: e.g., Adrenaline, Dopamine, Melatonin
Each type differs in structure and origin, leading to distinct actions and target organs.
Key Hormones and Their Roles in the Body
Thyroid Hormone
Thyroid hormone is the body’s “metabolism accelerator”, regulating how fast energy is burned and influencing nearly every organ system. In young children, it is essential for brain development.
The thyroid gland resembles a butterfly and is located at the front of the neck, just below the Adam’s apple. It produces and releases hormones into the bloodstream and is part of the endocrine system.
Common Thyroid Disorders
Thyroid problems are relatively common—particularly in women, who are several times more likely to be affected than men. Common conditions include:
- Hypothyroidism: Underactive thyroid.
- Hashimoto’s thyroiditis: Chronic autoimmune inflammation of the thyroid gland, the most common cause of hypothyroidism.
- Graves’ disease: An autoimmune condition that leads to overproduction of thyroid hormones.
- Thyroiditis: Inflammation of the thyroid gland.
- Thyroid nodules: Lumps in the thyroid gland, either single or multiple.
- Thyroid cancer: A malignant growth caused by abnormal cell proliferation in the thyroid gland.
When to See a Doctor for Thyroid Evaluation
Because thyroid hormones regulate metabolism, too much can make your body “run too fast,” and too little can make it “run too slow.” Common symptoms include:
- Unexplained weight gain or weight loss
- Abnormally slow or rapid heartbeat
- Unusual sensitivity to cold or heat
- Very dry or abnormally moist skin
- Irregular menstrual periods
If these symptoms occur, it’s advisable to see a doctor for a blood test to assess thyroid function and determine proper treatment.
Service available: Thyroid function testing.
Testosterone (for Men)
Testosterone is the primary male sex hormone, produced mainly by the testes and in smaller amounts by the adrenal glands. It influences sexual function, blood and muscle systems, fat distribution, bone health, mood, and daily energy levels.
Functions of Testosterone
- Stimulates male puberty: genital development, body hair growth, deepening of the voice, broader shoulders, and increased muscle mass
- Supports sexual performance and libido
- Stimulates red blood cell production and boosts energy
- Increases muscle mass and reduces fat storage
- Maintains bone density and lowers the risk of osteoporosis
- Affects skin and sebaceous glands (may cause acne in some men), sweat, and body odor
- Influences mood, focus, and confidence
Signs of Low Testosterone
- Decreased energy, fatigue, lack of vitality
- Mood swings, irritability, apathy, or depression
- Reduced libido, weaker morning erections, lower sperm count
- Loss of muscle mass, increased abdominal fat, weight gain
- Poor sleep quality or sleep disturbances
- Decline in exercise performance and slower recovery
Female Sex Hormones
Testosterone in Women
Although testosterone is often referred to as a “male hormone,” women produce it as well. The female body synthesizes androgens (including testosterone) from the ovaries, adrenal glands, and in smaller amounts from fat and skin tissues. Women typically have testosterone levels that are only about 1/10 to 1/20 of those in men, yet this hormone plays a vital role in energy, mood, sexual function, muscle mass, and bone health.
Functions of Testosterone in Women
- Supports sexual desire and arousal
- Enhances vitality, focus, and mood
- Maintains muscle mass and strength, helps reduce abdominal fat
- Increases bone density, lowering the risk of osteoporosis
- Promotes vaginal and skin health, moisture, and comfort
- Influences breast health and overall body composition
Effects of Low Testosterone in Women
- Reduced sexual response and libido
- Fatigue, low energy, irritability, or depression
- Decreased muscle mass, increased fat, reduced exercise performance
- Vaginal dryness and discomfort during intercourse
- Decreased bone density and osteoporosis risk
Effects of High Testosterone in Women
- Oily skin and acne / excess body hair
- Male-pattern hair loss (thinning at the crown)
- Irregular periods, anovulation, infertility
Estrogens and Progesterone
These are the two primary female sex hormones, produced mainly by the ovaries. They work together to regulate the menstrual cycle, pregnancy, and female sexual characteristics.
Estrogen
- Physical development: Promotes hip widening, breast development, and a softer voice
- Menstrual cycle regulation: Thickens the uterine lining during the first half of the cycle
- Bone health: Increases bone mass and density
- Brain and mood: Supports memory and emotional stability
Progesterone
- Prepares the uterus for pregnancy: After ovulation, it thickens and stabilizes the uterine lining
- Maintains pregnancy: Prevents uterine contractions and prepares the breasts for milk production
- Regulates menstruation: Drops in progesterone levels trigger menstruation if pregnancy does not occur
Adrenal Cortex Hormones
The adrenal cortex, located above each kidney, produces steroid hormones essential for regulating metabolism, blood pressure, and stress responses.
Related Disorders
- Cushing’s syndrome
- Caused by excessive cortisol due to adrenal tumors or long-term steroid use
- Symptoms: round “moon” face, fat at the back of the neck (buffalo hump), thin limbs, fragile skin, muscle weakness, high blood pressure, high blood sugar
- Addison’s disease
- Caused by insufficient adrenal hormone production
- Symptoms: fatigue, weight loss, poor appetite, nausea, diarrhea, and skin darkening
- Adrenal insufficiency
- Inadequate hormone production by the adrenal glands or pituitary dysfunction
When to See a Doctor
- Rapid, unexplained weight gain (especially around the abdomen)
- Unintentional weight loss
- Abnormal skin darkening or purple stretch marks
- Persistent fatigue despite rest
- Abnormally high or low blood pressure
- High blood sugar levels
- Muscle weakness
- Mood swings, depression, or irritability
- Irregular menstrual cycles
Cortisol
Cortisol is a steroid hormone produced by the adrenal cortex. It helps the body respond to physical and emotional stress and regulates key functions such as inflammation, metabolism of sugar, fat, and protein, as well as water and electrolyte balance. Cortisol directly affects energy, mood, blood pressure, and the immune system.
Effects of Cortisol Imbalance
- Excess Cortisol (High Levels):
- Weight gain (especially in the midsection), moon face, buffalo hump
- High blood sugar and blood pressure, muscle weakness, thin skin, bruising, acne
- Mood swings, sleep disturbances, lowered immunity
- Cortisol Deficiency (Low Levels):
- Severe fatigue, weight loss, poor appetite, dizziness or fainting, low blood pressure
- Nausea, vomiting, abdominal pain, electrolyte imbalances
- May indicate Addison’s disease or adrenal fatigue
Dehydroepiandrosterone (DHEA)
DHEA is a steroid hormone produced by the adrenal cortex, serving as a precursor for several other hormones—especially estrogen and testosterone. Levels peak in early adulthood (ages 20–25) and gradually decline with age. DHEA is linked to energy, resilience, and stress response.
Functions of DHEA
- Acts as a precursor for sex hormones
- Supports mood regulation and stress resilience
- Helps maintain muscle mass, bone density, and healthy body composition
- Influences immune function and inflammation
- Plays a role in metabolism and weight control
- Supports brain function, memory, and daily vitality
Effects of DHEA Imbalance
- Chronic fatigue, low energy, poor focus
- Poor sleep quality
- Easy weight gain and abdominal fat accumulation
- Low mood, irritability, or depression
- Decreased sexual function
- Reduced bone density and weakened immunity
Aldosterone
Aldosterone is a steroid hormone produced by the zona glomerulosa of the adrenal cortex. Its primary role is to regulate electrolyte and fluid balance and maintain blood pressure. It signals the kidneys (and parts of the large intestine) to reabsorb sodium and water into the bloodstream while excreting potassium through urine. This increases blood volume and helps keep blood pressure within a healthy range.
Why Aldosterone Matters
- Maintains blood pressure and circulation
- Regulates sodium–potassium balance
- Affects the heart, muscles, and nervous system
Excess Aldosterone
Occurs in Primary hyperaldosteronism, often due to a benign adrenal tumor. Common features:
- High blood pressure resistant to medication
- Low potassium (may cause weakness, cramps, heart palpitations)
- Increased blood volume, sometimes with swelling
Low Aldosterone
Seen in Addison’s disease or adrenal insufficiency. Symptoms may include:
- Low blood pressure, dizziness, fainting, fatigue, weight loss, poor appetite
- High potassium and low sodium
Melatonin
Melatonin is a hormone produced by the pineal gland in the brain. It acts as a biological signal that tells the body when it’s time to sleep. In low-light or dark environments, melatonin is released into the bloodstream, inducing drowsiness. Levels typically rise in the evening, peak at night, and decline after sunrise, reaching their lowest in the late morning.
Key Functions of Melatonin
- Initiates and maintains sleep
- Helps adjust the body clock during jet lag or shift work
- Supports immune function and has antioxidant effects
Possible Side Effects
- Usually mild and temporary: daytime drowsiness, headache, dizziness, nausea
- Rare: mood changes, restlessness, low blood pressure, vivid dreams
Precautions:
Pregnant or breastfeeding women and individuals on medications that interact with melatonin (e.g., blood thinners, anticonvulsants, immunosuppressants) should consult a physician before use.
Ways to Support Natural Melatonin
- Get 10–20 minutes of morning sunlight after waking
- Dim lights and avoid screens 1–2 hours before bedtime, or use blue light filters
- Keep a consistent sleep schedule
- Avoid caffeine after noon and alcohol before bed
- Keep the bedroom dark, quiet, and cool (18–24 °C)
- Exercise regularly, but avoid intense cardio before sleep
When to See a Doctor
- Insomnia ≥ 3 nights/week for more than 3 months
- Nonrestorative sleep with loud snoring or sleep apnea
- Regular use of sleeping pills or alcohol to fall asleep
- Underlying health conditions or multiple medications and considering melatonin supplements
Service available: Hormone balance testing
Growth hormone (GH)
Growth hormone is a protein-based hormone produced by the pituitary gland. It promotes growth, tissue repair, and regeneration. After secretion, GH stimulates the liver and other tissues to produce Insulin-like growth factor 1 (IGF-1), which drives growth in bones, muscles, and organs.
Benefits of Growth Hormone
- Supports Growth in Children
GH is essential for organ development and overall growth during childhood. It stimulates the liver to produce IGF-1, which promotes chondrocyte proliferation at the growth plates, helping children grow taller and develop a strong skeletal structure. - Improves Sleep
GH secretion peaks during deep sleep, helping promote restorative rest. Adults with low GH may experience insomnia, and supplementation may improve sleep quality and reduce nighttime awakenings. - Delays Aging & Enhances Vitality
GH levels naturally decline with age (about 14% per decade), contributing to decreased strength, increased fat, reduced physical performance, and mood changes. Supporting GH levels may help slow aging processes and preserve vitality. - Enhances Sexual Function
GH improves blood flow and stimulates nitric oxide production, which helps men maintain erections and supports vaginal lubrication in women, improving sexual health. - Boosts Metabolism
GH promotes protein synthesis, reduces protein breakdown, and enhances fat utilization. This supports healthy weight management, lean muscle gain, and metabolic balance.
Insulin-like growth factor 1 (IGF-1)
IGF-1 is a natural growth factor hormone that plays a critical role in physical development, particularly during childhood and adolescence when growth is most rapid. It is produced in the liver under the stimulation of GH from the pituitary gland. IGF-1 then acts on the growth plates of bones to increase length and size, directly affecting height and skeletal development.
Benefits of IGF-1
- Promotes height growth in children and adolescents by stimulating bone elongation during growth spurts
- Supports muscle growth by enhancing protein synthesis and cell proliferation
- Increases bone density and strength, reducing the risk of osteoporosis
- Accelerates recovery from exercise or illness by stimulating tissue repair and regeneration
- Supports growth balance in children with developmental delays, helping them achieve normal or above-average height and physical development
Reference:
1.Thyroid Hormone: What It Is & Function.
2.Hypogonadism in Men.
3.Hypothalamic-Pituitary-Ovarian Axis Disorders Impacting Female Fertility
4.Physiology, Aldosterone.
5.Melatonin: What You Need To Know
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