What Does CF Stand For in Five Feet Apart? Understanding Cystic Fibrosis

October 1, 2025 •

4 min read

According to the Cystic Fibrosis Foundation, CF is a life-shortening, hereditary disease affecting over 30,000 people in the U.S. alone. If you are wondering what does CF stand for in Five Feet Apart, the acronym refers to this very condition, which forms the core of the film's romantic drama plot.

Quick Summary

The article explains that CF stands for Cystic Fibrosis, the genetic disorder affecting the main characters in the movie Five Feet Apart. It details the disease's effects on the respiratory and digestive systems, discusses the real-life infection control guidelines, and compares the film's portrayal with the lived experience of CF patients.

Key Points

CF stands for Cystic Fibrosis: In Five Feet Apart, the acronym refers to a severe, progressive genetic disease that affects the lungs and other organs.
Thick Mucus is a Key Symptom: The genetic defect causes the body to produce thick, sticky mucus that clogs airways and traps bacteria, leading to chronic infections.
The 'Six-Foot Rule' is Real: CF patients must stay a safe distance (ideally six feet or more) from each other to prevent the spread of dangerous, contagious bacteria.
The Movie Took Creative Liberties: While the film raised awareness, it was criticized for romanticizing the dangerous act of breaking the six-foot rule and not fully representing the realities of CF.
CF Affects Multiple Systems: Beyond the lungs, CF impacts the digestive system, pancreas, and reproductive organs, requiring extensive daily care.
Life Expectancy Has Improved Significantly: Thanks to medical advancements, the life expectancy for CF patients has increased dramatically, though it remains a serious illness.

What is Cystic Fibrosis (CF)?

Cystic Fibrosis, or CF, is a severe, progressive genetic disease that causes persistent lung infections and limits the ability to breathe over time. The disease is caused by a defective gene that produces a faulty protein, known as the cystic fibrosis transmembrane conductance regulator (CFTR). This protein is responsible for regulating the flow of salt and water in and out of cells. When the protein is not working correctly, it causes thick, sticky mucus to build up in various parts of the body, most notably the lungs, pancreas, and other organs.

The Impact on the Lungs

The most commonly known aspect of CF is its effect on the respiratory system. The thick mucus in the lungs can clog airways and trap germs, leading to chronic infections, inflammation, and eventual respiratory failure. For patients like the characters in Five Feet Apart, this necessitates a grueling daily routine of treatments, including airway clearance techniques and nebulized medications, to help clear the mucus and maintain lung function. The risk of cross-infection between CF patients is particularly high and dangerous, as they can carry different antibiotic-resistant bacteria that are especially virulent to others with CF. This reality is the foundation for the famous "six-foot rule" that dictates the plot of the film.

The Impact Beyond the Lungs

CF is a multi-system disease that affects more than just the lungs. The buildup of thick mucus also impacts the digestive system and other parts of the body.

Here are some of the ways CF affects other organ systems:

Digestive System: The mucus can block ducts in the pancreas, preventing digestive enzymes from reaching the intestines. This leads to poor absorption of nutrients, requiring many patients to take enzyme supplements with every meal.
Liver: Blocked bile ducts in the liver can cause liver disease.
Reproductive System: In men, CF can cause infertility due to blocked tubes that connect the testes and prostate gland.
Sweat Glands: A common symptom of CF is unusually salty sweat, which is often used in the initial diagnostic 'sweat test'.

The “Six-Foot Rule” and the Movie's Plot

Central to the narrative of Five Feet Apart is the "six-foot rule," a real-life infection control guideline that dictates the distance CF patients must maintain from one another. In the film, Stella and Will, both CF patients, decide to "take back a foot," reducing the distance to five feet as a symbol of their rebellion against the disease that dictates their lives.

The reasoning behind this rule is crucial to understanding the characters' dilemma. While a healthy immune system can typically fight off various airborne bacteria, CF patients' compromised respiratory systems are especially vulnerable. They can carry different strains of bacteria in their lungs, and swapping these germs through close contact poses a life-threatening risk. The film effectively captures the emotional weight of this physical separation, making the characters' longing for touch both heart-wrenching and medically precarious.

Fact vs. Fiction in Five Feet Apart

While Five Feet Apart brought much-needed attention to cystic fibrosis, its portrayal drew mixed reviews from the CF community. Many appreciated the heightened awareness, while others pointed out medical inaccuracies and the romanticization of the disease.


Feature	Film's Portrayal	Real-Life Experience	Accuracy Verdict	Comments
The 'Six-Foot Rule'	A central, dramatic premise that the main characters deliberately break.	A critical, non-negotiable safety guideline for patients. Breaking it is extremely dangerous and not common.	Romanticized	Emphasizes romance over medical reality.
Daily Treatment Regimen	Depicts characters adhering to rigorous daily treatments, like the vibrating vest.	Daily treatment is a constant, exhausting reality for many, involving nebulizers, vests, and a large number of pills.	Mostly Accurate	Captures the physical burden of the disease well.
Hospital Environment	Shows CF patients congregating freely in hospital hallways.	Hospitals have strict protocols to prevent cross-infection, with CF patients often having to remain in their rooms or use separate wings.	Inaccurate	Exaggerates hospital procedures for dramatic effect.
Life Expectancy	Can portray characters as being gravely ill at a young age.	While CF is a serious illness, advancements in treatment have significantly improved life expectancy. Many patients live into their 40s and beyond, leading full lives.	Slightly Outdated	Focuses on a worst-case scenario that doesn't reflect the majority of cases today.
Mental Health	Touches on the depression and anxiety associated with chronic illness.	Many with CF experience significant mental health challenges due to the constant treatment burden, hospital stays, and limitations.	Accurate	Acknowledges the emotional toll of living with CF.

The film's creators did consult with real CF patients, including the late CF activist Claire Wineland, who sadly passed away from complications after a lung transplant following the film's completion. Her input helped ground some of the medical realities, even if the central romantic premise remained a point of contention for many within the CF community. The film's primary strength is raising awareness for a condition that remains relatively invisible to the general public.

Conclusion

In the movie Five Feet Apart, CF stands for Cystic Fibrosis, a life-altering genetic disease that necessitates strict infection control, such as the six-foot rule, for patient safety. While the film successfully brought this often-misunderstood condition to the mainstream, it also took creative liberties that romanticized the dangers of cross-infection. For those seeking to learn more about the realities of living with CF, it's important to recognize that the movie is a dramatization and that real-life experiences can vary significantly. By understanding the true meaning of CF, viewers can gain a deeper appreciation for the daily challenges and incredible resilience of people living with this chronic illness.

Learn more about the latest research and support for cystic fibrosis by visiting the Cystic Fibrosis Foundation.

Frequently Asked Questions

People with CF cannot hug each other because they are at risk of cross-infection. They carry different bacteria in their lungs, and close physical contact, like hugging, could allow these bacteria to spread from one person to another, leading to dangerous and potentially life-threatening infections.

While the specific story of Stella and Will is fictional, the movie was inspired by the real experiences of CF patients, including late activist Claire Wineland, who was hired as a consultant for the film.

Yes, for some people, CF can be an invisible disease. The physical symptoms are not always immediately obvious, but it requires a constant, rigorous daily treatment regimen and imposes significant health challenges on those living with it.

Significant advancements in medicine have dramatically increased the life expectancy for CF patients. Where people once lived only into childhood or adolescence, many now live into their 40s, 50s, and beyond.

No, there is currently no cure for cystic fibrosis. Treatment focuses on managing symptoms, preventing complications, and improving quality of life, but it remains a terminal illness.

The CFTR gene is the defective gene that causes cystic fibrosis. It is responsible for making a protein that regulates the flow of salt and water in cells. When the gene is mutated, this protein doesn't work correctly, leading to the buildup of thick mucus.

The movie is called Five Feet Apart because it refers to the moment when the characters, Stella and Will, defy the strict 'six-foot rule' for CF patients and decide to 'take back a foot' to get closer to each other.