The causes of hepatitis C are exclusively linked to transmission of the hepatitis C virus (HCV) through blood-to-blood contact. Unlike hepatitis A, which spreads through contaminated food or water, or hepatitis B, which spreads through bodily fluids including sexual contact, the causes of hepatitis C mainly involve direct exposure to infected blood. This makes it both preventable and manageable with proper medical care and harm-reduction practices.
The hepatitis C virus is a small RNA virus that belongs to the Flaviviridae family. It targets liver cells and, without treatment, can cause long-term inflammation and serious liver damage. Unfortunately, the virus is very good at causing chronic infection. In fact, around 85% of people who get infected don’t clear it on their own. That’s why hepatitis C is one of the leading causes of chronic viral hepatitis across the world.
Hepatitis C from Injecting Drug Use and Unsafe Healthcare
The most common way people get hepatitis C is by sharing needles or injecting equipment. People who inject drugs are at high risk, especially where sterile supplies and education are lacking. Even one shared needle is enough to spread the virus. In many wealthier countries, this remains the top cause of infection. Studies show that up to 90% of long-term injection drug users carry hepatitis C. It’s not just needles that carry risk—shared filters, water, or even tourniquets can also be sources of infection.
Unsafe medical or dental practices are another major cause. In some countries, people still get infected through poorly sterilised instruments, blood transfusions, or surgical tools. This usually happens when clinics don’t follow proper safety measures—like sterilising equipment, using gloves, or testing blood before transfusions. These situations are still common in many low- and middle-income countries.
Hepatitis C from Blood Products, Childbirth, and Work Exposure
Before the early 1990s, hepatitis C was often spread through blood transfusions and organ transplants. Screening of blood donors only began in the UK in 1991. People who had transfusions or transplants before this time—especially those treated for conditions like haemophilia—may have been infected unknowingly. Today, blood screening is standard, but in some places, poor oversight still puts people at risk.
Mothers with hepatitis C can also pass the virus to their babies. This is called vertical transmission. The risk is low—about 5–6%—but it increases if the mother also has HIV or a high amount of the virus in her blood. The infection usually happens during childbirth, not pregnancy. Breastfeeding is safe in most cases, unless the mother’s nipples are cracked or bleeding.
Healthcare workers also face risk, mostly through needlestick injuries or accidental exposure to blood. Though the chance of infection from a single needle prick is under 2%, it’s still a concern, especially in busy hospitals or emergency settings. Protective gear, training, and clear safety procedures are essential.
Other Causes: Sexual Contact, Tattoos, and Shared Items
Hepatitis C is not usually spread through sex, but it can happen—especially among men who have sex with men, or people with HIV. Risk also increases with rough sex, the presence of other STIs, or having multiple partners. While the chance of infection in a monogamous relationship is very low, people with high-risk sexual behaviour should consider getting tested.
Getting a tattoo or piercing with non-sterile tools can also spread hepatitis C. This risk is highest in unregulated places, like prisons or informal salons. Even sharing razors, toothbrushes, or other personal items that might carry tiny amounts of blood can be risky. However, in professional shops that follow strict hygiene rules, the risk is very low. People should always make sure single-use needles and sterilised tools are used.
At home, casual contact doesn’t spread hepatitis C. Hugging, kissing, or sharing dishes is safe. But if someone in the household has hepatitis C, it’s wise to avoid sharing sharp objects like nail clippers or razors. Accidents involving blood should be cleaned carefully using gloves and disinfectants.
Less Common and Rare Routes of Hepatitis C Infection
Other infections, like HIV or hepatitis B, can increase the chance of getting hepatitis C. For example, people with HIV are more likely to get hepatitis C through sex or drug use. Also, they may develop liver disease faster and need more complex treatment.
There are also a few rare ways people can become infected. In some dialysis units, if equipment isn’t cleaned properly, patients may be exposed. Traditional practices like scarification or blood rituals can also be risky. Even snorting drugs through shared straws may carry risk if blood is present in the nasal passages. In care homes, using glucose monitors or finger-prick devices without single-use lancets has also caused infections in rare cases.
In Summary
All causes of hepatitis C involve contact with infected blood. Whether through shared needles, poor medical hygiene, or other risky practices, these routes are largely preventable. Better education, access to sterile tools, and safer healthcare practices can greatly reduce new infections. As global awareness and treatment access improve, stopping the spread of hepatitis C becomes more achievable. Still, prevention is the simplest and most effective way to avoid the serious health problems this virus can cause.
