How do I know if my hair is damaged? Signs and home checks

Damaged hair gives itself away in daylight, not in the shower. Stand near a window, look at the surface of your hair and at the last few centimetres, and most of the answer is there in about a minute.

The confusing part is that several things feel like damage and are not. Coarse hair feels rough because it is coarse. Curly hair is drier than straight hair by nature, which the American Academy of Dermatology states plainly in its curly hair guidance. Neither of those is wear. This post separates the two, gives you the signs in the order they usually appear, and gives you three checks you can run at home.

What damage means on a single hair

A hair has an outer layer of flat overlapping cells called the cuticle, wrapped around an inner core. A 2023 review in Polymers describes the cuticle as about six to ten overlapping cells pointing towards the tip, arranged like roof shingles. When those scales lie flat, the strand is smooth, water-resistant and slippery against its neighbours.

Damage is that layer lifting, wearing thin, or coming away altogether, and in worse cases the inner core losing protein too. The same review makes the consequence clear: without the water-repelling surface, the fibre takes on more water, swells, and the friction between hairs goes up.

Here is the part that decides everything else. StatPearls describes the hair shaft above the skin as a cylinder of non-living keratinised cells. It has no blood supply and no way to rebuild itself. The Polymers review says the same thing in one sentence: hair is made of dead cells, so it cannot be biologically renovated.

So "is my hair damaged" is a useful question, and "how do I heal it" is not. The honest question underneath is how much of the length is worn, how fast it is getting worse, and what you keep.

The signs you can see

Look at your hair in daylight, dry, and brushed the way you normally wear it.

Split tips are the clearest sign. One hair divides into two or three at the end, sometimes several centimetres up. In dermatology this has a name, trichoptilosis, and it starts where the cuticle wears through and exposes the core.

Short broken pieces standing up along your parting are the second sign. These are hairs that snapped in the middle of their length rather than shedding from the root. Shedding 50 to 100 hairs a day from the root is normal, according to the American Academy of Dermatology. Pieces two to eight centimetres long, with a blunt or frayed end rather than a small white bulb, are breakage.

A matte surface is the third. Smooth, flat cuticle scales reflect light in one direction, which is what shine is. A dermatology review of shampoos and conditioners in the Indian Journal of Dermatology explains that flattening the cuticle scales increases the reflectance of light, which improves shine and colour. Worn scales do the reverse and scatter the light, so the hair reads flat and colourless even when the colour itself has not changed.

The fourth is a visible change at one point along the length. Your ends look paler, thinner and wispier than your mid lengths, and the change happens at one clear line rather than gradually. That line is usually the last time you cut, or the level your bleach or your flat iron reaches.

The signs you can feel

Take one strand between your thumb and first finger and draw it slowly from the root towards the tip. Healthy hair feels the same the whole way down. Damaged hair catches. You can usually name the exact centimetre where the feel changes.

Tangling is the second thing you feel, and it is a direct result of the surface. Lifted scales hook onto their neighbours. The Polymers review ties it to lost lipids: the fibre becomes more water-attracting, swells, and friction between the fibres goes up. If your comb has started to stop halfway down when it used to run through, that is a surface report, not bad luck.

Third, the feel when wet. Wet damaged hair often feels soft in a way that is not pleasant, almost slippery and formless, because water has entered a fibre that no longer resists it. Wet healthy hair feels slippery too, and springs back when you squeeze it. The difference is the spring.

Fourth, the feel of the last two centimetres between wet and dry. If the ends feel dry and stiff when dry, and unusually soft when wet, the outer layer in that section is largely gone.

The signs that only show up over weeks

Some signs need time, which is why people miss them.

Colour that fades within two or three washes is one. A porous strand takes dye in fast and lets it out fast. If your colour used to last six weeks and now it is gone in ten days, the strand changed, not the dye.

A style that will not hold is another. A blow dry that drops by lunchtime, or curls that relax within two hours, point at the inside of the hair rather than the outside. We wrote about the test for that in hair elasticity and what it means for your cut, and the reading it gives is the most useful single number about your hair.

Third, length that stops. Hair that never passes the shoulders, year after year, is almost never a growth problem. Scalp hair grows at about 0.35 mm a day, so roughly a centimetre a month, according to StatPearls. When the ends break off at the same speed, the length sits still. There is more on that in the guide to split ends and breakage.

Three checks that take five minutes

Do all three. One on its own can mislead.

The daylight check. Stand at a window, hold a section of hair away from your head, and look for a band of light running along it. Healthy hair reflects a visible band. Damaged hair reads even and dull with no band anywhere. Bathroom lights sit overhead and light the top of your head instead of the length, which is why hair looks worse there and why this check has to happen at a window.

The single-strand slide. One hair, thumb and finger, root to tip, slowly. Mark the point where it starts to catch. Then measure from that point to the tip. That distance is what a stylist needs to hear, and it is the number that decides whether a trim fixes it.

The wet section check. After washing, before any product, take a section from the back of your head and a section from near your face and squeeze the water out of each. Compare how they feel. The front section takes the heat and the sun and the brush, so it is usually worse. A clear difference between the two sections means the cause is something you are doing, not something inside the hair.

Damage, or is that just your hair

This is where most advice goes wrong, and it costs people money on products aimed at a problem they do not have.

Coarse hair has a wide diameter and feels rough between the fingers whatever condition it is in. The test is the slide: coarse hair feels thick and even the whole length, while damaged hair changes as you move down.

Curly and coily hair tangles by design, because the strand changes direction repeatedly and hairs wrap around each other. The American Academy of Dermatology notes that curly hair is drier than other hair types and recommends detangling wet with a leave-in and a wide-tooth comb. Tangling alone is not evidence of damage here. Breakage during detangling is.

Fine hair looks see-through at the ends even when it is in good condition, because fewer strands make a thinner section. Compare the same section against a plain wall six months apart rather than against someone else's hair.

Hair that has always been this way is texture. Hair that was different a year ago is damage. That single question sorts most cases.

How far up the strand does it go

Once you know there is damage, the useful measurement is where it starts, because that decides what happens next.

Damage in the last two to three centimetres is normal wear on the oldest part of the hair. The American Academy of Dermatology points out that the ends are the oldest and most fragile part of the hair and should get the conditioner. A regular trim keeps this permanently under control.

Damage that reaches the mid lengths means the cause is ongoing, not historic. Something in the current routine, a flat iron, a daily tight ponytail, a bleach that has been refreshed through the length, is still doing it, and cutting alone will not hold.

Damage that reaches close to the root is rare from styling and points at a chemical service, a scalp problem, or something medical. That is a dermatologist question. The American Academy of Dermatology says plainly that if changing how you care for your hair does not help, you should see one.

Whether to cut the damaged part off, and how much, is its own decision with real trade-offs. We laid it out in should I cut off damaged hair.

What caused it, ranked honestly

The American Academy of Dermatology lists ten habits that damage hair. Read in order of how much they usually matter, the list looks like this.

Chemical services first. Colouring, perming and relaxing change the inside of the strand. The AAD advice is to stretch touch-ups to every 8 to 10 weeks or longer in dry weather, never to have two chemical services at once, and to condition after every wash.

Heat second, and specifically heat used often. The AAD recommendation is the lowest heat setting, less contact time, and using these tools about once a week or less. Once a week is a long way from most people's habit, and that gap is where a lot of damage lives.

Mechanical force third. Brushing wet, a hundred strokes a day, tight ponytails, buns and braids, and heavy extensions. The AAD line on brushing is direct: hair never needs a hundred strokes a day, and that is a myth.

Washing technique fourth, and it is smaller than the others. Rubbing shampoo down the length instead of massaging it into the scalp, rubbing with a towel instead of wrapping, and skipping conditioner.

The thing people get wrong is treating damage as a product problem. It is almost always a habit problem with a product-shaped solution attached. The Kurli team

What to do once you know

Three actions, in this order.

Stop the cause. There is no point conditioning an end that a flat iron will meet again on Tuesday. Pick the single habit from the list above that you do most often and change that one first.

Cut what has gone past use. A split that has travelled up the strand keeps travelling, and no product closes it permanently. Products can smooth a split temporarily so it looks and behaves better, which is a real effect and a short one.

Protect what is left. Conditioner on every wash, concentrated on the ends. A wide-tooth comb instead of a brush on wet hair. Less heat, lower heat. Looser ties.

If you want the reading done on your own photographs rather than from a list, the Kurli AI Specialist looks at three pictures of your hair, says what it sees in the texture, the ends and the scalp, and writes the routine around that. The wider picture of how hair condition and a haircut work together is in hair before the cut.

One last thing worth saying. Almost everybody with hair past their shoulders has some damage at the ends, because those ends are years old and have had years of handling. Finding damage is not a failure. Knowing where it starts is what turns it into a decision.