firstdegree relatives (parent, sibling, or child), have a higher risk of developing HL compared with people who do not have first-degree relatives with the disease. ■ Siblings of patients with HL have a three- to seven-fold increased risk of developing this disease, and the risk is higher in identical twins. However, since the incidence of HL in the general population is extremely low, the risk of a first-degree relative developing HL is still very rare. ■ Fewer than one percent of patients with HL have a family history of the disease. Learning the Basics 18 Part 1 Table 1.2. Known Risk Factors for Hodgkin Lymphoma (continued) HL cannot be caused by injury and cannot be caught from someone who has the disease. While parents, children, and siblings of patients with HL have a slightly increased risk of developing this disease compared with the general population, there are no clearly identifiable genetic or hereditary factors that can predict this slightly increased risk. Therefore, routine screening for HL among the immediate family members of patients with HL is not recommended. Gender ■ Overall, men have a slightly higher risk of developing HL than women; however, women are more likely to be diagnosed with the nodular sclerosis subtype. Immunodeficiency Disorders ■ People with inherited (for example, common variable immunodeficiency disorder, X-linked lymphoproliferative disorder) or acquired (for example, chronic immunosuppression that may occur following a solid organ transplant or treatment of certain immune conditions such as juvenile rheumatoid arthritis) are at an increased risk of developing HL. Infection by Certain Viruses ■ People infected with the Epstein-Barr virus (EBV; the virus that can cause infectious mononucleosis) or the human immunodeficiency virus (HIV; the virus that can cause acquired immunodeficiency syndrome [AIDS]) have a higher risk of developing HL compared with people who have not been infected with these viruses. 19 Understanding Hodgkin Lymphoma Chapter 2: Seeking Medical Attention This chapter explains the signs and symptoms of Hodgkin lymphoma (HL) and discusses how a doctor determines whether a person has the disease. A sign is anything unusual that doctors, nurses, or physician assistants notice when they examine their patients or look at their laboratory test results. A symptom is anything unusual in a normal body function, appearance, or sensation that a patient experiences. During a visit with a healthcare practitioner, patients should report all of their symptoms to their doctor, nurse, or physician assistant. Symptoms may indicate the presence of HL or another disease. What Are the Signs and Symptoms of HL? Some patients with HL do not have any obvious signs or symptoms of the disease. Their doctors might detect the lymphoma during routine blood tests and/or a physical examination. For others, the lymphoma is discovered when symptoms occur and patients go to the doctor because they are worried, uncomfortable, or not feeling well. As shown in Table 2.1, HL may cause different signs and symptoms depending on where it is located in the body. Keep in mind that many of these signs and symptoms are not specific to HL and may be due to other conditions. Part 1 — Learning the Basics Learning the Basics 20 Part 1 Table 2.1. Signs and Symptoms Commonly Found in Patients With HL When Should a Patient Seek Medical Attention? Anyone who has an enlarged lymph node that does not return to normal size within one month and is greater than one centimeter in size (unless it is located in the groin) and/or persistent symptoms should see a doctor to make sure that lymphoma or another serious condition is not present. A good rule of thumb is to seek medical attention if any of the signs or symptoms listed in Table 2.1 last longer than two weeks, or sooner if the symptoms are severe enough to impact daily life. It is important to note that most patients with these symptoms do not have lymphoma, as diseases or conditions not related to lymphoma may cause many of these symptoms. Sign or Symptom Possible Reasons Lumps under the skin on the sides of the neck, above the collarbone, or in the underarms, elbows, or groin Lymph nodes,