Urology Blog - Dr. Petronio Melo

Micropenis: Understand the Causes, Diagnoses, and Available Treatments



What is Micropenis

Urology is a field of medicine that encompasses various conditions affecting the male reproductive and urinary system. One of these conditions is micropenis, a rare anatomical disorder that occurs when an adult man’s penis is significantly smaller than the average. According to the medical definition, a micropenis in adult men is an erect penis measuring less than 7.5 cm.

The condition, usually diagnosed shortly after birth, can lead to feelings of embarrassment, frustration, and even depression. However, it’s crucial to note that a man with micropenis can have a fully satisfying sex life and is perfectly capable of urinating standing up, meaning the condition does not interfere with the organ’s basic functions.

Importance of the Discussion

Although micropenis is an uncommon condition, affecting about 0.6% of the male population, it’s vital to have an open and honest discussion on the subject. Due to the cultural and social significance often attributed to penis size, many men with micropenis might feel isolated or ashamed, hesitating to seek medical help or emotional support.

Our society often jokes about penis size, but for men living with micropenis, this is far from a laughing matter. This constant ridicule can lead to feelings of inadequacy, anxiety, and depression. Thus, it’s essential to talk openly about micropenis to dispel myths and stigmas, offering support and understanding to those living with the condition.

The Role of Urology

Urology plays a vital role in treating micropenis, offering therapeutic solutions ranging from hormone therapy to surgery for men seeking treatment for the condition. Furthermore, urologists can provide insights and guidance on living with micropenis, emphasizing that sexual function is not solely determined by penis size.

Purpose of this Article

This article aims to provide detailed and accurate information on micropenis, including its causes, diagnosis, and treatment options. We hope that by informing readers about what micropenis is, we can help normalize the condition, debunk misunderstandings, and offer valuable resources to those who might be grappling with it. For those faced with the diagnosis, it’s essential to remember that medical and psychological support is available, and a fulfilling and satisfying sex life is entirely attainable.

What is Micropenis?

Defining Micropenis

Micropenis is a condition characterized by a penis that, when flaccid and stretched, measures more than 2.5 standard deviations below the average. This is the most widely accepted definition in the medical community and is established in diagnostic manuals. To simplify understanding, this can be translated into measurements: in adult men, a micropenis is typically defined as an erect penis measuring less than 7.5 cm, a size considerably below the global average, which ranges from 12 to 16 cm when erect.

The Anatomy of Micropenis

A micropenis possesses all the anatomy of a regular penis – spongy body, cavernous bodies, urethra, glans, and foreskin – just on a smaller scale. This means that, despite its size, a micropenis can perform all expected functions: it allows the passage of urine and ejaculation, and is sensitive to touch and can become erect.

It’s worth noting that micropenis is not a disease, but a physical condition. The individual’s overall health is not affected by the presence of a micropenis, and except for specific situations addressed later in this article, the penis size does not influence fertilization capability.

Micropenis vs. Small Penis

It’s important to highlight the difference between a small penis and a micropenis. Many men are concerned about their penis size, but it’s crucial to remember that there’s a broad and normal range of sizes. Some men might have a penis smaller than the average, but that doesn’t necessarily classify them as having a micropenis. Diagnosing micropenis involves a specific measurement, as previously mentioned, and doesn’t merely apply to all men with a penis size below average.

Facts and Myths

Many myths surround micropenis, mainly due to the lack of open discussions and the limited amount of information available. One such myth is that men with a micropenis cannot have a satisfying sex life. This is untrue. While some sexual positions may be more challenging, with communication, experimentation, and perhaps the use of sexual aids, men with micropenis can have a fulfilling and gratifying sex life.

Another common myth is that men with micropenis cannot become fathers. This is also not true. Penis size is not related to sperm production or fertilization capability. Except for a few specific cases where micropenis is part of a more complex condition that may include infertility, a man with a micropenis can become a father.

How Common is Micropenis?

Prevalence of Micropenis

Firstly, it’s important to emphasize that micropenis is a relatively rare condition. The exact prevalence can vary according to different sources, but most scientific studies estimate that micropenis occurs in about 0.6% of the male population. In other words, approximately 6 out of every 1000 men are born with a micropenis. This frequency is quite low compared to other urological conditions.

The Diversity of Sizes is Normal

A wide variation in penis size is entirely normal and natural. Just as people vary in height, weight, and other physical characteristics, the same goes for penis size. The average size for an erect penis, according to various scientific research, ranges from 12 to 16 cm. However, many men have an erect penis that is slightly smaller or larger than this average, and this is perfectly within the norm.

The Importance of Differentiation

Many men unnecessarily worry about the size of their penis, mainly due to misguided ideas propagated by society and popular culture. It’s crucial to understand that having a penis smaller than average is not the same as having a micropenis. As mentioned earlier, the diagnosis of micropenis is linked to a specific measurement and not a simple comparison with the average.

Reducing the Stigma

The fact that micropenis is a rare condition might contribute to the stigma surrounding it. However, it’s important to remember that having a micropenis does not interfere with an individual’s overall health, the ability to have a satisfying sex life, or the possibility of becoming a father. Moreover, treatments are available for those who feel discomfort with their penis size.

Open discussion and education are essential tools to combat the stigma around micropenis. Therefore, it’s of utmost importance to talk about the topic, raising awareness among people and providing accurate and updated information.

Causes of Micropenis

Hormonal Factors

The causes of micropenis are typically attributed to hormonal abnormalities. During gestation, the formation and development of the penis are influenced by hormones, particularly testosterone. The male fetus begins to produce testosterone around the seventh week of gestation, and it’s this testosterone that promotes penis growth.

Some conditions can affect the production or action of testosterone, resulting in a smaller-sized penis. Among them are:

  • Hypogonadotropic hypogonadism: A condition where the body produces little or no gonadotropin, the hormones that stimulate the activity of the testicles.
  • 5-alpha reductase deficiency: A rare genetic condition where the body can’t convert testosterone to its more active form, dihydrotestosterone (DHT), which plays a significant role in male sexual development.
  • Androgen insensitivity syndrome: A genetic condition where the body is partially or completely unable to respond to androgens, including testosterone.

Genetic Factors

Genetics can also play a role in the occurrence of micropenis. Some chromosomal disorders, such as Klinefelter syndrome (characterized by an extra X chromosome in males, resulting in an XXY configuration instead of the usual XY), may be associated with micropenis.

It can also occur due to genetic mutations that affect growth hormone signaling or testosterone action. However, in many cases of micropenis, the specific genetic cause is not identified.

Other Possible Causes

There are other possible causes for micropenis, though they are less common. Some of these include exposure to certain medications or chemicals during gestation that can interfere with fetal sexual development. Additionally, conditions that cause generally slow or delayed growth, like certain metabolic diseases or pituitary gland dysfunctions, may also result in micropenis.

Diagnosis of Micropenis

When Micropenis is Typically Identified

Micropenis is usually identified at birth during the newborn’s initial physical examination. This is because, in general, the condition is evident due to the abnormally small size of the penis. However, in some cases, micropenis may not be identified until puberty, when the expected penis growth does not occur.

The Diagnostic Process

The diagnosis of micropenis is based on physical measurements. To determine if a penis is considered micropenis, the doctor will measure the length of the penis in a flaccid and stretched state. For newborns and children before puberty, the standard penis size is typically 2.5 to 3.0 cm for newborns and 5.0 to 6.5 cm for children aged 5 to 13. During puberty, the average penis size increases, and a size below 7.5 cm when stretched is considered micropenis.

Additional Tests

While the measurement of the penis is the primary diagnostic criterion, the doctor might order additional tests to help ascertain the underlying cause of micropenis. These tests may include:

  • Hormonal Tests: These tests measure the levels of various hormones in the blood, including testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Changes in these hormonal levels can suggest certain medical conditions that might result in micropenis.
  • Imaging Tests: In some cases, imaging tests, such as ultrasound or magnetic resonance imaging, might be required to assess the internal structure of the penis and testicles.
  • Genetic Tests: If a genetic condition is suspected, genetic tests might be conducted to confirm the diagnosis.

Early diagnosis of micropenis is crucial to ensure that the individual receives the appropriate treatment and support. While micropenis can be a challenging condition, with proper care and treatment, individuals with micropenis can lead a healthy and satisfying life.

Psychological and Social Impact of Micropenis

Psychological Repercussions

Having a micropenis can have a significant impact on an individual’s mental health and emotional well-being. Society often associates penis size with masculinity and sexual performance, and these perceptions can lead to feelings of embarrassment, inadequacy, and low self-esteem in men with micropenis.

Depending on the severity of these feelings, some men might develop more serious conditions, such as depression, anxiety, or even body dysmorphic disorder (BDD) – a mental condition in which an individual is obsessively concerned with a perceived defect in their appearance.

Social Repercussions

Socially, micropenis can affect an individual’s life in various ways. There might be a negative impact on forming intimate relationships due to the fear of rejection or ridicule. Men with micropenis may avoid social situations that might expose them to potential humiliation, like using public restrooms or locker rooms, or engaging in activities that might reveal their penis size, such as swimming or other sports.

The Importance of Psychological Support and Counseling

Given the potentially severe impact of micropenis on an individual’s mental health and social life, psychological support and counseling are essential components of treatment. Specialized mental health professionals can offer effective coping strategies, assist in boosting self-esteem, and address any underlying mental health conditions, such as depression or anxiety.

Counseling can be particularly beneficial in helping men with micropenis develop a more positive and realistic view of their masculinity and sexual worth, which is not solely defined by penis size.

Support Groups

Support groups can also be a valuable source of comfort and understanding. Speaking with others going through similar experiences can be incredibly therapeutic and can help alleviate feelings of isolation or embarrassment. Moreover, these groups can provide a platform for sharing coping strategies and useful advice.

Treatment Options for Micropenis

Hormonal Therapy

One of the first steps in the treatment of micropenis might be hormonal therapy. This is especially true if the micropenis is caused by a hormonal deficiency. Administering certain hormones over a period can stimulate penis growth. This is generally the first line of treatment, especially for newborns and adolescents.

  • Human Growth Hormone (HGH): This hormone, also known as somatotropin, is administered to stimulate growth and development in children and teenagers.
  • Testosterone: The primary male hormone, testosterone, is administered to stimulate penis growth and the development of other secondary male characteristics.

It’s important to emphasize that timing is crucial for hormonal therapy. Once puberty is complete and bones stop growing, the effectiveness of hormonal therapy in increasing penis size diminishes significantly.


If hormonal therapy doesn’t result in significant growth, surgery may be an option. There are various surgical techniques available for penis elongation, but all come with potential risks and complications.

  • Phalloplasty: This is the medical term for penis elongation surgery. There are various different techniques, including releasing the penis’s suspensory ligament, transferring tissue to the penis, and the use of post-operative traction devices.
  • Penile Prosthesis Insertion: In cases where sexual function is affected, a penile prosthesis can be implanted. This not only increases penis size but also allows for normal erectile function.

It’s vital that patients are fully informed about the risks and benefits of any surgical procedure. This includes a realistic understanding of expectations in terms of size and function after surgery.

Other Considerations

  • Penis Traction Devices: Some studies suggest that penis traction devices can result in some elongation. However, these devices should be used with caution and under the supervision of a healthcare professional to prevent injuries.
  • Psychological Counseling and Sexual Therapy: For many men, micropenis has a greater impact on their psychological and emotional health than their physical health. Counseling and sexual therapy can be extremely helpful in these cases. Working with a therapist can assist men in feeling more confident in their bodies and enhance their sexual life and relationships.

Conclusion: A Comprehensive Perspective on Micropenis

In this article, we’ve delved into the condition known as micropenis, a condition where a man’s penis size is significantly below average. We’ve covered medical definitions, causes, prevalence, diagnosis, psychosocial impact, and treatment options. Each topic offers meaningful insights that, we hope, contribute to a deeper understanding and a more informed discussion about micropenis.

Summary of Key Points

Definition and Prevalence of Micropenis: Micropenis is a rare condition that affects less than 1% of the male global population. It’s clinically defined as a penis that, when stretched, measures more than 2.5 standard deviations below the average for age and stage of puberty.

Causes of Micropenis: Micropenis can be brought on by a variety of factors, including genetic conditions like Klinefelter syndrome, and hormonal conditions such as hypogonadism and androgen insensitivity. In some instances, the cause of micropenis may remain unknown.

Diagnosis of Micropenis: The diagnosis of micropenis is typically made by a physician through the measurement of the stretched penis length. Early diagnosis is pivotal as it allows for more effective and timely intervention.

Psychological and Social Impact: Micropenis can have significant psychological repercussions, including low self-esteem, anxiety, and depression. Psychological support and counseling can be immensely beneficial.

Treatment Options: Treatment options for micropenis range from hormonal therapy, surgery, and the use of penile traction devices. The choice of treatment depends on several factors, including the underlying cause of micropenis, the patient’s age, and personal preferences.

Final Conclusion

Micropenis is a multifaceted condition that can substantially impact a man’s life. However, with a clear understanding of the condition and access to appropriate counseling and treatment, men with micropenis can lead healthy and fulfilling lives.

One must never forget that support, guidance, and appropriate counseling are fundamental in dealing with any medical condition, and micropenis is no exception. Always seek professional medical help if you or someone you know is grappling with this condition. As a urologist and robotic surgeon, I’m always available to assist and provide guidance wherever possible.

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Dr. Petronio Melo

CRM-SP 157.598 – RQE 70.725

  • Ph.D. from the Faculty of Medicine, University of São Paulo (USP)
  • Certified in Robotic Surgery by Intuitive Surgical
  • Member of the American Urological Association (AUA)
  • Member of the Brazilian Society of Urology (SBU)



Dr. Petronio Melo

CRM-SP 157.598

– Urologista, Andrologista e Cirurgião Robótico

– Certificação em Cirurgia Robótica pela Intuitive Surgical (Sunnyvale, Califórnia, EUA).

– Doutorado na Faculdade de Medicina da Universidade de São Paulo (USP)


Agende com um especialista

Se você ou alguém que você conhece está lidando com micropênis, lembre-se de que não está sozinho e que ajuda está disponível. O primeiro passo é sempre buscar aconselhamento médico especializado.

Reconhecemos que lidar com a condição de micropênis pode ser um desafio emocional e físico. Por isso, é crucial conversar com um especialista em urologia que possa esclarecer suas dúvidas, discutir suas preocupações e fornecer orientações claras sobre as opções de tratamento disponíveis.

Se você está em busca de um especialista em urologia e cirurgia robótica, convido-o a entrar em contato com nosso consultório na Vila Mariana, São Paulo. Oferecemos um ambiente seguro e confortável para discutir suas preocupações e esclarecer suas dúvidas sobre o micropenis.

Nosso endereço é Rua Domingos de Morais, 2187, Bloco Paris – conj. 210, Vila Mariana, São Paulo, SP, Brasil, CEP 04035-000. Se preferir, você também pode entrar em contato conosco por telefone nos números (11) 91060-1374 e (11) 2659-4092.

Se preferir, pode visitar nosso site www.drpetroniomelo.com.br para saber mais sobre os serviços que oferecemos e marcar uma consulta online.

Micropênis é uma condição complexa que exige orientação médica apropriada. Através de uma abordagem personalizada e centrada no paciente, estou comprometido em fornecer o apoio necessário e as melhores opções de tratamento para cada indivíduo.

Por favor, não hesite em entrar em contato. Estamos aqui para ajudá-lo.

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