How your body heals after everyday cuts and scrapes

June 4th, 2020

As soon as you cut your finger on a kitchen knife or scrape your knee in a fall, your body begins a complex process to heal the wound.

Below, Michelle Lage, a physical therapist and wound care specialist with UCHealth SportsMed Clinic – Steamboat Springs, describes how wounds heal and how you can best help the healing along.

Four phases of wound healing

Immediately after you cut yourself, platelets collect in the area to form a clot and stop the bleeding. That’s the first phase of wound healing, known as hemostasis.

a woman wraps a Band-Aid around her finger to start the wound healing process.
There are four phases of wound healing after you cut your finger or skin your knee. Photo: Getty Images.

Next is the inflammatory phase, in which white blood cells clear the wound of debris, infection or bacteria.

After that, healthy cells migrate to the wound site for the proliferation phase. “The new tissue builds from the edges of the wound and causes skin contraction,” Lage said.

And finally, the remodeling or maturation phase takes place, in which the wound site is strengthened.

Smaller cuts may fully heal in a week, while larger lacerations can take an entire year.

Addressing chronic wounds

Sometimes, wounds get stuck in the inflammation phase.

“It happens for a lot of reasons,” Lage said. “If there’s a large infection, or if a wound is overrun by natural skin bacteria, or if the area was radiated for cancer or a person has diabetes — anything that will slow the body’s natural ability to heal itself can cause the wound to get stuck.”

Wounds that last for more than two weeks with no change or show any sign that infection may have become chronic should be checked out by a medical provider.

How to care for a wound

Wounds should be kept clean and moist to promote healing.

“A lot depends on how it’s taken care of when it happens,” Lage said. “If you get a cut and ignore it, you’ll form a scab. Bacteria can get under that scab if it dries or cracks, setting it up for delayed healing.”

When cleaning a wound, use saline solution or sterile water, which most closely resembles the body’s natural fluids, to flush out any debris that may have entered the wound.

“Soap is very drying, and chlorine and additives in tap water aren’t natural,” Lage said. “You want to be as gentle to the area as possible.”

Keep a wound covered when showering, then after the shower, cleanse the wound with water or saline solution and redress it.

Use a very thin layer of a single or double antibiotic ointment, avoiding the triple antibiotic ointments such as Neosporin, as they can sometimes cause irritation.

“The wound needs to be able to breathe and balance moisture,” Lage said.

Wounds shouldn’t get too dry or too wet, as both conditions can delay healing.

An adhesive bandage can be used to cover smaller wounds, keeping in mind that some people are sensitive to adhesives. If a wound is draining, add gauze.

“It should be relatively covered with no openings that would allow air in and cause it to dry out,” Lage said.

When to see a doctor

For any wound that won’t stop bleeding, you should go to the emergency department immediately.

Wounds that are very red and hot, cause streaks on nearby skin, have yellow or green drainage or pus, are very swollen or are surrounded by skin that has become hard may be infected, so should be seen by a medical professional. And any wounds that may have become chronic warrant a trip to the doctor’s office.

“I’ve seen people who had an open spot on their leg for six months,” Lage said. “Maybe they fell, and the cut started to get better, but then it stayed the same and never healed. Those shouldn’t be ignored. If you’re not sure what to do, go ahead and see a physician.”

About the author

Susan Cunningham lives in the Colorado Rocky Mountains with her husband and two daughters. She enjoys science nearly as much as writing: she’s traveled to the bottom of the ocean via submarine to observe life at hydrothermal vents, camped out on an island of birds to study tern behavior, and now spends time in an office writing and analyzing data. She blogs about writing and science at susancunninghambooks.com.