Going a long time without washing your hair can cause a buildup of a yeast-like fungus called Malassezia on your scalp. Over time, this leads to a layer of dead skin cells that shed from your head in the form of oily, yellow-ish dandruff flakes.
Washing the hair less often can help the scalp remain healthy, prevent itching and flaking, and keep the hair soft and shiny. People with very oily scalps may develop acne on the scalp or along the hairline and may need to wash their hair more frequently to keep their hair looking clean.
For the average person, every other day, or every 2 to 3 days, without washing is generally fine. “There is no blanket recommendation. If hair is visibly oily, scalp is itching, or there's flaking due to dirt,” those are signs it's time to shampoo, Goh says.
When you don't wash your hair for 3 or more days or if your scalp is naturally oily, the oils your scalp produces naturally gets accumulated near your hair shafts. While this alone can cause itching and irritation in your scalp, it is ultimately the overgrowth of yeast that causes the throbbing pain in your hair.
Another leading cause of an itchy scalp is dirty hair. If you don't wash your hair regularly enough – dirt, oil, and product build-up can cause your scalp to become itchy and irritated. When your hair is too dirty, it can also lead to unwanted bacteria, sometimes turning into dandruff and other scalp problems.
Daily shampooing is an absolute must if you have a scalp condition, such as dandruff or seborrheic eczema. It is also important if you have fine hair, as this hair texture has more sebaceous glands and therefore becomes oily quickly at the roots.
If you are not washing your hair enough, this can contribute to your scalp hurting. Your hair won't get enough stimulation if you are not washing or brushing it regularly. This can cause a build-up of oil and flakes in your hair, which will irritate your scalp.
People with oily hair or who use hair care products daily should consider washing their hair once every 1–2 days. People with dry hair can wash their hair less frequently. Those with textured or coily hair should only wash it once every 1–2 weeks.
“The scalp is incredibly rich in blood supply, nerve endings, and oil glands. Additionally, this yeast (pityrosporum) builds up, leading to dandruff. The combination of these factors can cause inflammation, which translates to sensitivity that can feel like your hair hurting.”
Not washing your hair can lead to sebaceous secretion which can cause infection of the hair follicles. If you have dandruff, it tends to get mixed with the sebaceous secretion, increasing the risk of folliculitis. “Folliculitis causes inflammation of the hair follicles that can result in infection.
"The average individual can typically go 2 to 3 days without shampooing their hair. However, if your hair is visibly oily, you may not want to wait that long," she says. "Usually, you can go longer without washing your hair when your hair is styled up, but no one should ever go more than 14 days."
Sprinkle some baby powder on your hands and then run your fingers through your hair while focusing on the roots because that's where most oil gets collected. It will instantly soak up the grease and make your hair look fresh instantly. Sans chemicals, this DIY alternative won't irritate the skin.
Not washing the hair regularly with shampoo has certain advantages like cost and time saving, reduced exposure to chemicals, and less risk of hair damage. However, it may increase the risk of scalp irritation and infections due to the buildup of sebum, dirt, and sweat.
Benefits of Skipping a Wash
Washing your hair daily can strip your scalp of its natural microbiome and can cause dryness and inflammation. Over washing can also leave your hair brittle, limp and thin. If you have highlights or colored hair, less water exposure will ensure the color lasts longer.
Hair traps moisture, Lamb said, meaning that built-up bacteria on unwashed scalps can start to pick up a mildewy or sour smell after several days or a week, especially if exercise is involved.
Going a long time without washing your hair can cause a buildup of a yeast-like fungus called Malassezia on your scalp. Over time, this leads to a layer of dead skin cells that shed from your head in the form of oily, yellow-ish dandruff flakes. Dandruff can also make your scalp red, scaly, and itchy.
Hair Washing Frequency and Tips
“I recommend washing your hair two to three times a week,” Dr. Icecreamwala says. “If your hair is dry, you may only want to wash it twice a week. If it is on the oilier side, every other day is recommended.”
Migraines, headaches, and autoimmune disorders can cause scalp pain, irritation, and inflammation. Sunburns, rashes, wounds, and insect bites are also common causes of scalp tenderness. Most cases of scalp tenderness clear up on their own or with medication, but some are signs of an underlying condition.
Most cases of scalp pain are not serious and can be treated with home remedies such as taking pain relievers, applying heat or ice, or massaging the scalp. However, if the pain persists or is accompanied by other symptoms such as a rash, it is best to see a doctor to rule out any underlying medical conditions.
Hair is at its most fragile when wet, so if you go to bed with it damp and proceed to toss and turn against a pillow, you run a higher risk of breakage. But aside from being rough on your delicate strands, hitting the pillow with damp hair puts you at risk of developing skin infections, primarily on your scalp.
What can cause sores or scabs on the scalp? Sores or scabs on the scalp are often harmless and clear up on their own. However, they can sometimes be a sign of a condition that may require treatment, such as psoriasis, contact dermatitis, or head lice.