Lymphedema can be classified into two main types: primary and secondary. Each type has distinct causes and risk factors.

Primary lymphedema is a rare, inherited condition caused by developmental abnormalities in the lymphatic system. It can present at birth, during puberty, or in adulthood, depending on the specific genetic mutation involved. There are three main types of primary lymphedema:

1. Congenital Lymphedema: This type is present at birth and is often caused by a condition known as Milroy disease. It results from mutations in genes responsible for the development and function of the lymphatic vessels.
2. Lymphedema Praecox: Also known as Meige disease, this type typically develops around puberty or during pregnancy. It is the most common form of primary lymphedema and is associated with genetic mutations that affect lymphatic vessel formation.
3. Lymphedema Tarda: This type appears in adulthood, usually after the age of 35. It is the least common form of primary lymphedema and is often linked to genetic mutations that disrupt the lymphatic system's function later in life.

Secondary lymphedema is more common and results from damage to the lymphatic system due to external factors. These can include surgery, radiation therapy, infection, or injury. The following are some common causes of secondary lymphedema:

1. Cancer Treatments: Surgeries that involve lymph node removal, such as mastectomies for breast cancer, can damage lymphatic vessels and nodes, leading to lymphedema. Radiation therapy can also cause scarring and inflammation in lymphatic tissues, further contributing to the risk.
2. Infections and Inflammation: Certain infections, such as cellulitis or filariasis (caused by parasitic worms), can damage lymphatic vessels. Chronic inflammatory conditions, such as rheumatoid arthritis, can also impair lymphatic function.
3. Trauma and Injury: Physical trauma, burns, or severe injuries that affect the lymphatic system can lead to secondary lymphedema. Surgical procedures, especially those involving the removal or damage of lymph nodes, can also be a significant risk factor.
4. Obesity: Excess body weight can put additional pressure on the lymphatic system, leading to its dysfunction. Obesity is a significant risk factor for developing secondary lymphedema, particularly in the lower extremities.

The symptoms of lymphedema can vary depending on the severity and location of the swelling. Common signs and symptoms include:

• Swelling: The most noticeable symptom is persistent swelling in the affected limb(s), which may worsen over time. The swelling can cause a feeling of heaviness or tightness in the limb.
• Skin Changes: The skin over the swollen area may become thickened, hardened, or develop a leathery texture. This condition is known as fibrosis.
• Pain and Discomfort: Lymphedema can cause pain, aching, or discomfort in the affected area. The pain may be constant or intermittent.
• Reduced Range of Motion: Swelling and tissue changes can limit the range of motion in the affected limb, making it difficult to move or perform daily activities.
• Recurring Infections: Individuals with lymphedema are at an increased risk of developing infections in the affected area. The compromised lymphatic system can make it harder to fight off infections, leading to recurrent bouts of cellulitis or lymphangitis.

Several factors can increase your risk of developing lymphedema. Understanding these risk factors can help you take preventive measures and seek early intervention if needed.

Age

Lymphedema can affect individuals of all ages, but certain age groups are more susceptible. For instance, primary lymphedema can present at different stages of life, including infancy, adolescence, or adulthood, depending on the genetic mutation involved. 

Secondary lymphedema, however, is more commonly seen in older adults, particularly those who have undergone cancer treatments or have chronic health conditions.