Cigarette smoking, both active and passive, increases the risk of cervical cancer. Among HPV-infected women, current and former smokers have roughly two to three times the incidence of invasive cancer. Passive smoking is also associated with increased risk, but to a lesser extent.

Smoking has also been linked to the development of cervical cancer. Smoking can increase the risk in women a few different ways, which can be by direct and indirect methods of inducing cervical cancer. A direct way of contracting this cancer is a smoker has a higher chance of CIN3 occurring which has the potential of forming cervical cancer. When CIN3 lesions lead to cancer, most of them have the assistance of the HPV virus, but that is not always the case, which is why it can be considered a direct link to cervical cancer. Heavy smoking and long-term smoking seem to have more of a risk of getting the CIN3 lesions than lighter smoking or not smoking at all. Although smoking has been linked to cervical cancer, it aids in the development of HPV which is the leading cause of this type of cancer. Also, not only does it aid in the development of HPV, but also if the woman is already HPV-positive, she is at an even greater likelihood of contracting cervical cancer.

Long-term use of oral contraceptives is associated with increased risk of cervical cancer. Women who have used oral contraceptives for 5 to 9 years have about three times the incidence of invasive cancer, and those who used them for 10 years or longer have about four times the risk.

With the decrease in the death rate among people with HIV/AIDS receiving new treatments in the 1990s, the rates and severity of epidemic KS also decreased. However, the number of people living with HIV/AIDS is increasing in the United States, and it is possible that the number of people with AIDS-associated Kaposi sarcoma will again rise as these people live longer with HIV infection.

Although the exact cause of vulvar cancer isn't known, certain factors appear to increase your risk of the disease.

- Increasing age

- Exposure to human papillomavirus

- Smoking

- Being infected with the human immunodeficiency virus (HIV)

- Having a history of precancerous conditions of the vulva

- Having a skin condition involving the vulva

Some conditions such as lichen sclerosus, squamous dysplasia or chronic vulvar itching may precede cancer. In younger women affected with vulvar cancer, risk factors include low socioeconomic status, multiple sexual partners, cigarette use and cervical cancer. Patients that are infected with HIV tend to be more susceptible to vulvar cancer as well. Human papillomavirus (HPV) infection is associated with vulvar cancer.

Cancer of the stomach, also called gastric cancer, is the fourth-most-common type of cancer and the second-highest cause of cancer death globally. Eastern Asia (China, Japan, Korea, Mongolia) is a high-risk area for gastric cancer, and North America, Australia, New Zealand and western and northern Africa are areas with low risk. The most common type of gastric cancer is adenocarcinoma, which causes about 750,000 deaths each year. Important factors that may contribute to the development of gastric cancer include diet, smoking and alcohol consumption, genetic aspects (including a number of heritable syndromes) and infections (for example, "Helicobacter pylori" or Epstein-Barr virus) and pernicious anemia. Chemotherapy improves survival compared to best supportive care, however the optimal regimen is unclear.

Since many, if not most, anal cancers derive from HPV infections, and since the HPV vaccine before exposure to HPV prevents infection by some strains of the virus and has been shown to reduce the incidence of potentially precancerous lesions, scientists surmise that HPV vaccination may reduce the incidence of anal cancer.

On 22 December 2010, the U.S. Food and Drug Administration approved Gardasil vaccine to prevent anal cancer and pre-cancerous lesions in males and females aged 9 to 26 years. The vaccine has been used before to help prevent cervical, vulvar, and vaginal cancer, and associated lesions caused by HPV types 6, 11, 16, and 18 in women.

The Center for Disease Control and Prevention (CDC) included certain types of non-Hodgkin's lymphoma as AIDS-defining cancers in 1987. Immune suppression rather than HIV itself is implicated in the pathogenesis of this malignancy, with a clear correlation between the degree of immune suppression and the risk of developing NHL. Additionally, other retroviruses such as HTLV may be spread by the same mechanisms that spread HIV, leading to an increased rate of co-infection. The natural history of HIV infection has been greatly changed over time. As a consequence, rates of non-Hodgkin's lymphoma (NHL) in people infected with HIV has significantly declined in recent years.

Pancreatic cancer is the fifth-most-common cause of cancer deaths in the United States, and the seventh most common in Europe. In 2008, globally there were 280,000 new cases of pancreatic cancer reported and 265,000 deaths. These cancers are classified as endocrine or nonendocrine tumors. The most common is ductal adenocarcinoma. The most significant risk factors for pancreatic cancer are advanced age (over 60) and smoking. Chronic pancreatitis, diabetes or other conditions may also be involved in their development. Early pancreatic cancer does not tend to result in any symptom, but when a tumor is advanced, a patient may experience severe pain in the upper abdomen, possibly radiating to the back. Another symptom might be jaundice, a yellowing of the skin and eyes.

Pancreatic cancer has a poor prognosis, with a five-year survival rate of less than 5%. By the time the cancer is diagnosed, it is usually at an advanced, inoperable stage. Only one in about fifteen to twenty patients is curative surgery attempted. Pancreatic cancer tends to be aggressive, and it resists radiotherapy and chemotherapy.

Cholangiocarcinoma is a relatively rare form of cancer; each year, approximately 2,000 to 3,000 new cases are diagnosed in the United States, translating into an annual incidence of 1–2 cases per 100,000 people. Autopsy series have reported a prevalence of 0.01% to 0.46%. There is a higher prevalence of cholangiocarcinoma in Asia, which has been attributed to endemic chronic parasitic infestation. The incidence of cholangiocarcinoma increases with age, and the disease is slightly more common in men than in women (possibly due to the higher rate of primary sclerosing cholangitis, a major risk factor, in men). The prevalence of cholangiocarcinoma in patients with primary sclerosing cholangitis may be as high as 30%, based on autopsy studies.

Multiple studies have documented a steady increase in the incidence of intrahepatic cholangiocarcinoma over the past several decades; increases have been seen in North America, Europe, Asia, and Australia. The reasons for the increasing occurrence of cholangiocarcinoma are unclear; improved diagnostic methods may be partially responsible, but the prevalence of potential risk factors for cholangiocarcinoma, such as HIV infection, has also been increasing during this time frame.

The American Cancer Society estimated that in 2014 about 7,060 new cases of anal cancer would be diagnosed in the United States (4,430 in women and 2,630 in men) . It is typically found in adults, average age early 60s.

In the United States, an estimated 800 to 900 people die of anal cancer annually.

Blood tests to detect antibodies against KSHV have been developed and can be used to determine whether a person is at risk for transmitting infection to their sexual partner, or whether an organ is infected prior to transplantation. However, these tests are not available except as research tools, and, thus, there is little screening for persons at risk for becoming infected with KSHV, such as people following a transplant.

HIV/AIDS has become a chronic rather than an acutely fatal disease in many areas of the world. Prognosis varies between people, and both the CD4 count and viral load are useful for predicted outcomes. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype. After the diagnosis of AIDS, if treatment is not available, survival ranges between 6 and 19 months. HAART and appropriate prevention of opportunistic infections reduces the death rate by 80%, and raises the life expectancy for a newly diagnosed young adult to 20–50 years. This is between two thirds and nearly that of the general population. If treatment is started late in the infection, prognosis is not as good: for example, if treatment is begun following the diagnosis of AIDS, life expectancy is ~10–40 years. Half of infants born with HIV die before two years of age without treatment.

The primary causes of death from HIV/AIDS are opportunistic infections and cancer, both of which are frequently the result of the progressive failure of the immune system. Risk of cancer appears to increase once the CD4 count is below 500/μL. The rate of clinical disease progression varies widely between individuals and has been shown to be affected by a number of factors such as a person's susceptibility and immune function; their access to health care, the presence of co-infections; and the particular strain (or strains) of the virus involved.

Tuberculosis co-infection is one of the leading causes of sickness and death in those with HIV/AIDS being present in a third of all HIV-infected people and causing 25% of HIV-related deaths. HIV is also one of the most important risk factors for tuberculosis. Hepatitis C is another very common co-infection where each disease increases the progression of the other. The two most common cancers associated with HIV/AIDS are Kaposi's sarcoma and AIDS-related non-Hodgkin's lymphoma. Other cancers that are more frequent include anal cancer, Burkitt's lymphoma, primary central nervous system lymphoma, and cervical cancer.

Even with anti-retroviral treatment, over the long term HIV-infected people may experience neurocognitive disorders, osteoporosis, neuropathy, cancers, nephropathy, and cardiovascular disease. Some conditions like lipodystrophy may be caused both by HIV and its treatment.

The most common chemotherapy used for non-Hodgkin lymphoma is R-CHOP.

HIV can be transmitted from mother to child during pregnancy, during delivery, or through breast milk, resulting in the baby also contracting HIV. This is the third most common way in which HIV is transmitted globally. In the absence of treatment, the risk of transmission before or during birth is around 20% and in those who also breastfeed 35%. As of 2008, vertical transmission accounted for about 90% of cases of HIV in children. With appropriate treatment the risk of mother-to-child infection can be reduced to about 1%. Preventive treatment involves the mother taking antiretrovirals during pregnancy and delivery, an elective caesarean section, avoiding breastfeeding, and administering antiretroviral drugs to the newborn. Antiretrovirals when taken by either the mother or the infant decrease the risk of transmission in those who do breastfeed. However, many of these measures are not available in the developing world. If blood contaminates food during pre-chewing it may pose a risk of transmission.

If a woman is untreated, two years of breastfeeding results in an HIV/AIDS risk in her baby of about 17%. Treatment decreases this risk to 1 to 2% per year. Due to the increased risk of death without breastfeeding in many areas in the developing world, the World Health Organization recommends either: (1) the mother and baby being treated with antiretroviral medication while breastfeeding being continued (2) the provision of safe formula. Infection with HIV during pregnancy is also associated with miscarriage.

Although most patients present without any known risk factors evident, a number of risk factors for the development of cholangiocarcinoma have been described. In the Western world, the most common of these is primary sclerosing cholangitis (PSC), an inflammatory disease of the bile ducts which is closely associated with ulcerative colitis (UC). Epidemiologic studies have suggested that the lifetime risk of developing cholangiocarcinoma for a person with PSC is on the order of 10%–15%, although autopsy series have found rates as high as 30% in this population.

Certain parasitic liver diseases may be risk factors as well. Colonization with the liver flukes "Opisthorchis viverrini" (found in Thailand, Laos PDR, and Vietnam) or "Clonorchis sinensis" (found in China, Taiwan, eastern Russia, Korea, and Vietnam) has been associated with the development of cholangiocarcinoma. Patients with chronic liver disease, whether in the form of viral hepatitis (e.g. hepatitis B or hepatitis C), alcoholic liver disease, or cirrhosis of the liver due to other causes, are at significantly increased risk of cholangiocarcinoma. HIV infection was also identified in one study as a potential risk factor for cholangiocarcinoma, although it was unclear whether HIV itself or other correlated and confounding factors (e.g. hepatitis C infection) were responsible for the association.

Infection with the bacteria "Helicobacter bilis" and "Helicobacter hepaticus" species can cause biliary cancer.

Congenital liver abnormalities, such as Caroli's syndrome (a specific type of five recognized choledochal cysts), have been associated with an approximately 15% lifetime risk of developing cholangiocarcinoma. The rare inherited disorders Lynch syndrome II and biliary papillomatosis have also been found to be associated with cholangiocarcinoma. The presence of gallstones (cholelithiasis) is not clearly associated with cholangiocarcinoma. However, intrahepatic stones (called hepatolithiasis), which are rare in the West but common in parts of Asia, have been strongly associated with cholangiocarcinoma. Exposure to Thorotrast, a form of thorium dioxide which was used as a radiologic contrast medium, has been linked to the development of cholangiocarcinoma as late as 30–40 years after exposure; Thorotrast was banned in the United States in the 1950s due to its carcinogenicity.

Of all cancers involving the same class of blood cell, 2.3% of cases are Burkitt lymphoma. Epstein-Barr virus infection is strongly correlated with this cancer.

Lymphoma is the most common form of hematological malignancy, or "blood cancer", in the developed world.

Taken together, lymphomas represent 5.3% of all cancers (excluding simple basal cell and squamous cell skin cancers) in the United States and 55.6% of all blood cancers.

According to the U.S. National Institutes of Health, lymphomas account for about 5%, and Hodgkin lymphoma in particular accounts for less than 1% of all cases of cancer in the United States.

Because the whole system is part of the body's immune system, patients with a weakened immune system such as from HIV infection or from certain drugs or medication also have a higher incidence of lymphoma.

A study conducted on 452 patients revealed that the genotype responsible for higher IL-10 expression makes HIV infected people more susceptible to tuberculosis infection. Another study on HIV-TB co-infected patients also concluded that higher level of IL-10 and IL-22 makes TB patient more susceptible to Immune reconstitution inflammatory syndrome (IRIS). It is also seen that HIV co-infection with tuberculosis also reduces concentration of immunopathogenic matrix metalloproteinase (MMPs) leading to reduced inflammatory immunopathology.

Primary cerebral lymphoma (or "primary central nervous system lymphoma") is a form of NHL. It is very rare in immunocompetent people, with an incidence of 5–30 cases per million person-years. However the incidence in immunocompromised individuals is greatly increased, up to 100 per million person-years.

Primary cerebral lymphoma is strongly associated with Epstein–Barr virus (EBV). The presence of EBV DNA in cerebrospinal fluid is highly suggestive of primary cerebral lymphoma.

Treatment of AIDS patients with antiretroviral drugs reduces the incidence of primary cerebral lymphoma.

Primary effusion lymphoma (PEL) is a B-cell lymphoma, presenting with a malignant effusion without a tumor mass.

Though heart disease is not exclusive to the poor, there are aspects of a life of poverty that contribute to its development. This category includes coronary heart disease, stroke and heart attack. Heart disease is the leading cause of death worldwide and there are disparities of morbidity between the rich and poor. Studies from around the world link heart disease to poverty. Low neighborhood income and education were associated with higher risk factors. Poor diet, lack of exercise and limited (or no) access to a specialist were all factors related to poverty, though to contribute to heart disease.

Both low income and low education were predictors of coronary heart disease, a subset of cardiovascular disease. Of those admitted to hospital in the United States for heart failure, women and African Americans were more likely to reside in lower income neighborhoods. In the developing world, there is a 10 fold increase in cardiac events in the black and urban populations.

When HIV-negative children take isoniazid after they have been exposed to tuberculosis, their risk to contract tuberculosis is reduced. A Cochrane review investigated whether giving isoniazid to HIV-positive children can help to prevent this vulnerable group from getting tuberculosis. They included three trials conducted in South Africa and Botswana and found that isoniazid given to all children diagnosed with HIV may reduce the risk of active tuberculosis and death in children who are not on antiretroviral treatment. For children taking antiretroviral medication, no clear benefit was detected.

More than 300 million people worldwide have asthma. The rate of asthma increases as countries become more urbanized and in many parts of the world those who develop asthma do not have access to medication and medical care. Within the United States, African Americans and Latinos are four times more likely to suffer from severe asthma than whites. The disease is closely tied to poverty and poor living conditions. Asthma is also prevalent in children in low income countries. Homes with roaches and mice, as well as mold and mildew put children at risk for developing asthma as well as exposure to cigarette smoke.

Unlike many other Western countries, the mortality rate for asthma has steadily risen in the United States over the last two decades. Mortality rates for African American children due to asthma are also far higher than that of other racial groups. For African Americans, the rate of visits to the emergency room is 330 percent higher than their white counterparts. The hospitalization rate is 220 percent higher and the death rate is 190 percent higher. Among Hispanics, Puerto Ricans are disporpotionatly affected by asthma with a disease rate that is 113 percent higher than non-Hispanic Whites and 50 percent higher than non-Hispanic Blacks. Studies have shown that asthma morbidity and mortality are concentrated in inner city neighborhoods characterized by poverty and large minority populations and this affects both genders at all ages. Asthma continues to have an adverse effects on the health of the poor and school attendance rates among poor children. 10.5 million days of school are missed each year due to asthma.

Estimates of the rate of HCV vertical transmission range from 2–8%; a 2014 systematic review and meta-analysis found the risk to be 5.8% in HCV-positive, HIV-negative women. The same study found the risk of vertical transmission to be 10.8% in HCV-positive, HIV-positive women. Other studies have found the risk of vertical transmission to be as high as 44% among HIV-positive women. The risk of vertical transmission is higher when the virus is detectable in the mother's blood.

Evidence does not indicate that mode of delivery (i.e. vaginal vs. cesarean) has an effect on vertical transmission.

For women who are HCV-positive and HIV-negative, breastfeeding is safe; however, CDC guidelines suggest avoiding breastfeeding if a woman's nipples are "cracked or bleeding" to reduce the risk of transmission.