Intravenous (IV) drug users are at risk for a range of health issues, including infectious diseases like hepatitis B and C, skin and soft-tissue infections (SSTIs), and HIV. Fever in IV drug users, also referred to as “Cotton Fever,” is a condition characterized by a systemic inflammatory response syndrome (SIRS) shortly after injecting substances into the human body.

What Is Cotton Fever?

Cotton fever is commonly experienced by intravenous drug abusers (IVDAs) who use cotton to filter their drugs. The bacteria in these cotton filters frequently cause it, commonly Enterobacter agglomerans, to enter the bloodstream. E agglomerans can contaminate the injection needle and, once injected, cause an immune reaction from the drug user. Other causes of cotton fever could be improper sterilization techniques while preparing drugs for injection or sharing injection equipment.

The Symptoms of Cotton Fever

The side effects of cotton fever appear shortly after injection and vary for different individuals, depending on the type of substance injected and the amount. While cotton fever’s symptoms are not life-threatening, it can lead to more severe health issues and infections in IVDAs. The symptoms are generally resolved within a day or two. The most common side effects and symptoms of cotton fever include:

  • Fever
  • Chills
  • Muscle aches and pain (myalgia)
  • Headaches
  • Malaise
  • Fatigue
  • Shortness of breath
  • Chest pain
  • Nausea

The Causes of Cotton Fever in Intravenous Drug Users

The most common cause of cotton fever is the bacteria in cotton filters, contaminating the needle and syringe for IVDAs. Using non-sterile needles, syringes, or other paraphernalia increases the risk of transferring bacteria and other pathogens into the bloodstream. Reusing or sharing injection equipment like needles can also transfer bacteria from one drug user to another, increasing the risk of cotton fever and other infectious diseases. Poor practices for preparing drugs for intravenous use, including dirty water or contaminated surfaces, can lead to bacterial contamination.

The environment in which IVDAs prepare their drugs and inject them can also be a source of bacterial contamination, causing cotton fever. Additionally, IV drug users who don’t practice good hygiene, like cleaning their equipment and the injection site, are at a higher risk for bloodstream infections.

The Risks of Cotton Fever on Health and Well-Being

Cotton fever is a symptom of broader health risks associated with IV drug use, such as recurring infections, blood-borne diseases, and drug abuse and addiction. Some IV drug users may avoid seeking medical treatment for cotton fever due to fear of legal repercussions, stigma, or lack of support. Delayed treatment of cotton fever can lead to more severe complications with health and well-being, especially if left untreated.

Recurring Infections

IV drug users are at risk of experiencing cotton fever multiple times, especially if they continue to use contaminated injection equipment or practice unsafe drug preparation techniques. Cotton fever can sometimes be a sign of more serious bacterial infections. The recurrence of bacteria in the bloodstream from IV drug use can weaken the immune system over time, making users more susceptible to various diseases and health complications. If left untreated, the underlying infection can spread and lead to conditions like endocarditis, sepsis, or abscesses at injection sites.

Infective endocarditis (IE) is a life-threatening inflammation of the heart lining called the endocardium caused by bacteria, fungi, or other germs entering the bloodstream. Sepsis is a life-threatening systemic infection, often starting in the lung, urinary tract, skin, or gastrointestinal tract. Skin abscesses from IV drug use, such as skin and soft-tissue infections (SSTI), often result from unsterile injection equipment or unclean skin. These SSTIs in IVDAs are commonly caused by the infectious agent, Staphylococcus aureus, entering the body.

Risk of Blood-Borne Diseases

Blood-borne diseases in injection drug users (IDU), commonly HIV or hepatitis B and C, are typically found when drug users share needles or injection equipment. Human immunodeficiency virus (HIV) weakens the immune system and the body’s ability to fight infections. If left untreated, HIV infections can progress to Acquired Immunodeficiency Syndrome (AIDS). Hepatitis B and C, viral infections affecting the liver, can lead to cirrhosis, chronic liver disease, and liver cancer. HIV and hepatitis are the most common blood-borne diseases among IV drug users; there is also a risk of infections such as syphilis and bacterial endocarditis.

Compounding Health Issues

IV drug abuse often co-occurs with other health and social challenges, such as malnutrition, homelessness, and mental health disorders. Nutritional deficiencies in IV drug users are common due to neglecting dietary needs and the necessary nutrients the body needs to be healthy. IV drug users with a substance use disorder (SUD) may begin to isolate themselves, potentially leading to job loss, strained personal relationships, and homelessness. These social and economic challenges can exacerbate the cycle of drug use and lead to more severe health issues and recurring cotton fever.

Mental health disorders and drug use commonly coincide due to the side effects of certain substances, as well as other factors, including social isolation, health problems, and homelessness. These factors contribute to drug abuse and mental health issues such as depression, anxiety disorders, and post-traumatic stress disorder (PTSD).

Risks of Drug Use and Addiction

Additionally, IV drug users carry the risk of vein damage as a result of repeated injections. This can damage and collapse the veins, making it challenging to find suitable injection sites for regular drug use and leading to an increased risk of infections. Regular substance use, especially IV drug use, carries a high risk of addiction and overdose, especially for those unsure of the contents of the drugs they’re injecting. Those addicted to IV drug use are often unconcerned about the purity and strength of the substances they’re using. This significantly raises the risk of experiencing lethal side effects, health issues, and overdose.

The most common drugs injected intravenously are heroin, methamphetamines, prescription stimulants, and prescription opioids. Opioids, such as the illegal drug heroin, are a powerful and addictive class of drugs with a high potential for abuse. Stimulants, such as methamphetamines, are another type of IV drug with an increased risk for dependency and addiction. Drug abuse and addiction in IV drug users extends beyond cotton fever, as it can result in a substance use disorder (SUD), increasing health risks, and potentially lethal overdose. Even prescription IV drug users are at risk for dependency and addiction, infectious diseases, and compounding health issues. It’s crucial to follow safe drug practices as advised by your healthcare professional to ensure safe IV drug use.


Drug abuse and addiction is not something you should be ashamed of or afraid to seek rehab treatment for. At Coastal Detox, we understand what you’re going through and want to be there for you. Reach out to us today to get in touch with one of our addiction professionals for treatment and drug detox in Stuart, FL.







  • National Library of Medicine, 2013. Acute infections in intravenous drug users.
  • PubMed, 2023. Systemic Inflammatory Response Syndrome.
  • National Library of Medicine, 2020. Cotton fever resulting in Enterobacter asburiae endocarditis.
  • Mayo Clinic, 2022. Endocarditis.
  • Centers for Disease Control and Prevention, 2023. What is Sepsis?
  • PubMed, 2002. Skin and soft tissue infections in injection drug users.
  • National Library of Medicine, 2013. Abscess and Self-Treatment Among Injection Drug Users at Four California Syringe Exchanges and Their Surrounding Communities.
  • Centers for Disease Control and Prevention, 2023. What is Viral Hepatitis?
  • Centers for Disease Control and Prevention, 2019. Increased Methamphetamine, Injection Drug, and Heroin Use Among Women and Heterosexual Men with Primary and Secondary Syphilis — United States, 2013–2017.
  • National Library of Medicine, 2011. Stimulant Abuse: Pharmacology, Cocaine, Methamphetamine, Treatment, Attempts at Pharmacotherapy.