What are cysts?
Cysts are noncancerous sacs that are typically filled with fluid, air, or a semi-solid substance like keratin. They can develop in a wide range of locations and for many different reasons. While the term "cyst" is often used to describe a benign, fluid-filled sac, it's a broad category encompassing hundreds of specific types. Most cysts are harmless and require no treatment, but some may cause pain, become infected, or indicate an underlying medical condition, making professional diagnosis important.
Common cyst locations and their causes
Cysts can form in myriad places, both externally and internally. The location often provides clues about the type of cyst and its potential cause.
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Skin (Epidermoid and Sebaceous Cysts): These are among the most common types of cysts and frequently appear on the face, neck, back, and torso. Epidermoid cysts form when a hair follicle gets blocked and skin cells accumulate beneath the surface. Sebaceous cysts, less common despite the similar name, arise from blocked sebaceous glands and contain an oily substance called sebum.
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Joints and Tendons (Ganglion Cysts): Often found on the hands, wrists, ankles, and feet, ganglion cysts are gel-filled lumps that develop near joints or tendons. The cause is often unknown, but they may result from repetitive motion or trauma that causes joint fluid to leak and form a sac.
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Ovaries (Ovarian Cysts): Very common during a woman's reproductive years, ovarian cysts are fluid-filled sacs that develop on or inside an ovary. Most are functional cysts that form as a normal part of the menstrual cycle, while others may be caused by conditions like polycystic ovary syndrome (PCOS).
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Breasts (Breast Cysts): These fluid-filled sacs are a common occurrence in breast tissue, often linked to hormonal changes. They can feel tender or painful and may fluctuate in size with the menstrual cycle.
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Kidneys (Renal Cysts): Simple renal cysts are often found incidentally during imaging and are typically harmless. However, some genetic conditions, such as polycystic kidney disease (PKD), can cause numerous cysts to form, potentially impacting kidney function.
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Behind the Knee (Baker's Cysts): This type of cyst forms behind the knee and is often associated with other knee problems, such as arthritis or a meniscus tear. It's caused by excess joint fluid bulging out and creating a fluid-filled sac.
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Lower Back (Pilonidal Cysts): Pilonidal cysts form in the skin of the lower back, near the cleft of the buttocks, and sometimes contain ingrown hairs. They can grow in clusters and become infected and painful, sometimes creating a cavity in the skin.
Factors influencing cyst formation
Beyond specific locations, several factors can contribute to cyst development:
- Blockages: A blocked duct or gland is a very common cause, such as in the case of sebaceous and Bartholin's cysts.
- Infections: Infections can cause a buildup of pus and other fluids, leading to abscesses or cysts, such as those seen in acne.
- Trauma: Damage to an area of the body can sometimes lead to cyst formation as part of the body's healing process.
- Genetics: Some conditions are directly linked to cyst formation, such as polycystic kidney disease and Gardner syndrome, which can cause epidermoid cysts.
- Hormonal Changes: Fluctuations in hormones can trigger certain cysts, most notably ovarian and breast cysts.
Comparison of common cyst types
| Cyst Type | Common Location(s) | Key Characteristics | Common Cause(s) |
|---|---|---|---|
| Epidermoid | Face, neck, torso, genital area | Filled with keratin; small punctum often visible | Blocked hair follicles |
| Ovarian | Ovaries | Often fluid-filled; size varies; may resolve on its own | Hormonal changes; follicular malfunction |
| Ganglion | Hands, wrists, feet, ankles | Gel-filled lump; feels like it rolls under the skin | Leaking joint fluid; overuse |
| Pilonidal | Lower back, near buttocks cleft | Contains hair and debris; can get infected | Ingrown hair; localized trauma |
| Breast | Breast tissue | Fluid-filled sac; may be tender; fluctuates in size | Hormonal changes |
| Baker's | Behind the knee | Fluid-filled swelling; associated with knee issues | Excess knee joint fluid due to injury or arthritis |
When to seek medical advice
While most cysts are benign, it's crucial to be aware of signs that warrant a doctor's attention. A medical professional can provide a proper diagnosis and rule out more serious conditions. It's recommended to consult a doctor if a cyst is rapidly changing in size, becomes painful or tender, appears red or inflamed, feels firm or solid, or if it ruptures and leaks fluid.
Additionally, any internal cyst causing significant symptoms, such as an ovarian cyst that causes severe abdominal pain or a kidney cyst that affects organ function, should be evaluated by a healthcare provider. For instance, certain ovarian cysts may be precancerous or cancerous growths and require biopsy. Therefore, seeking medical advice for any rapidly growing or unusual lump is always a good practice.
Conclusion
Cysts are common and can grow in nearly any part of the body, with their specific location and characteristics often revealing their type and cause. Whether on the skin or within internal organs, understanding where do cysts usually grow can help individuals identify common types and know when it’s appropriate to seek medical attention. The key is to be observant of changes in any lump and consult with a healthcare professional for accurate diagnosis and management. For more in-depth information on different types of cysts and their management, a resource like the Village Medical site provides comprehensive details on common cyst types. For an overall perspective on health and wellness, visit Healthline's resource on cysts.
