Cutting:
* Shorter Length: Obvious, but it alters the overall style and can change how your hair frames your face.
* Layering: Adds volume, texture, and movement. Can also make thick hair feel lighter or add fullness to thin hair.
* Shaping: Can enhance or detract from your facial features, highlight or soften angles.
* Damage Removal: Trims away split ends and damaged hair, improving its health and appearance.
* Bang/Fringe addition: changes the face shape and can hide or highlight different features.
Coloring:
* New Shade: Changes your hair's overall appearance, affecting how it complements your skin tone and eye color.
* Highlights/Lowlights: Adds dimension and depth, creating a more multi-tonal and textured look.
* Gray Coverage: Conceals gray or white hairs, restoring a more youthful appearance (if desired).
* Damage: Can weaken the hair shaft, making it dry, brittle, and prone to breakage, especially with bleaching or drastic color changes. Coloring lifts the cuticle of the hair shaft, and can change the hair's porosity.
* Irritation/Allergic Reaction: Some people are allergic to hair dye ingredients (particularly PPD), leading to scalp irritation, itching, swelling, or more severe reactions.
Styling (Heat, Products, etc.):
* Straightening: Creates a sleek, smooth, and often shiny appearance. Repeated heat styling can cause damage.
* Curling: Adds waves, curls, or ringlets, changing the texture and volume of the hair. Also can cause damage with repeated heat.
* Braiding/Updos: Creates various intricate styles, from simple braids to elaborate updos for special occasions. Tight styles can cause breakage and hair loss (traction alopecia).
* Volumizing: Adds lift and fullness to the hair, making it appear thicker and more voluminous.
* Hold/Control: Keeps the hair in place, preventing frizz, flyaways, and maintaining the desired style.
* Shine: Enhances the hair's natural shine, making it look healthy and vibrant.
* Damage: Overuse of heat styling tools, harsh chemicals in styling products, or tight hairstyles can lead to dryness, breakage, and damage.
* Buildup: Products can leave residue on the hair, making it look dull, greasy, and weighed down.
Chemical Treatments (Perms, Relaxers, Keratin Treatments):
* Texture Change: Permanently alters the hair's texture, either adding curls (perm) or straightening it (relaxer). Keratin treatments smooth the hair temporarily.
* Manageability: Can make hair easier to style and manage, depending on the treatment.
* Damage: These treatments are very harsh and can cause significant damage to the hair, leading to breakage, dryness, and thinning.
* Scalp Irritation: The chemicals can irritate the scalp, causing redness, itching, and even burns.
Washing and Conditioning:
* Cleanliness: Removes dirt, oil, and product buildup, leaving the hair feeling clean and fresh.
* Hydration: Replenishes moisture to the hair, making it softer, smoother, and more manageable.
* Detangling: Makes it easier to comb or brush the hair, preventing breakage.
* Improved Appearance: Enhances the hair's shine, volume, and overall appearance.
* Damage: Over-washing can strip the hair of its natural oils, leading to dryness. Harsh shampoos can also be damaging.
Other Factors to Consider:
* Hair Type: The effects of any hair treatment or style will vary depending on your hair type (straight, wavy, curly, coily; fine, medium, thick; dry, normal, oily).
* Hair Condition: Healthy hair will generally withstand styling and treatments better than damaged hair.
* Products Used: The quality and ingredients of the products you use can significantly impact the health and appearance of your hair.
* Technique: How you perform the styling or treatment also matters. Using proper techniques can minimize damage.
* Frequency: How often you perform the action will affect the outcome. Daily heat styling will likely damage hair more than occasional.
To give a more specific answer, you would need to specify *what* "it" is that you are doing to your hair. For example, "What happens when I bleach my hair?" or "What happens when I use a curling iron on my hair?" would get you more targeted and helpful responses.