Several environmental and biological factors contribute to increased hair fall during hot weather.

1. Excessive Sweating on the Scalp

During summer, the scalp produces more sweat.

When sweat mixes with:

• Oil
• Dirt
• Pollution
• Dead skin cells

it can clog hair follicles and create an unhealthy scalp environment.

This may lead to:

• Scalp irritation
• Itching
• Inflammation
• Increased hair shedding

A healthy scalp is essential for healthy hair growth.

2. Increased Sun Exposure

Just like your skin, your hair and scalp are affected by UV radiation.

Prolonged sun exposure can:

• Weaken hair shafts
• Dry out the scalp
• Damage hair proteins
• Increase brittleness and breakage

Many people confuse hair breakage caused by sun damage with actual hair fall.

3. Dehydration

Summer heat increases water loss from the body.

When hydration levels drop:

• Hair becomes dry and fragile
• The scalp loses moisture
• Hair strands become more prone to breakage

Even mild dehydration can affect overall hair health.

4. Oily Scalp and Product Build-Up

Hot and humid weather stimulates sebaceous glands, leading to excess oil production.

This can result in:

• Greasy scalp
• Dandruff flare-ups
• Follicle blockage
• Increased hair shedding

Many patients with oily scalps notice worsening hair fall during summer because of this buildup.

5. Seasonal Hair Growth Cycle Changes

Hair naturally goes through different growth phases:

Anagen Phase: Active growth stage.

Catagen Phase: Transition stage.

Telogen Phase: Resting and shedding stage.

During summer, a greater number of hairs may enter the telogen phase, leading to increased shedding.

This phenomenon is generally temporary but can become more noticeable in people already prone to hair loss.

6. Scalp Infections Become More Common

Heat and humidity create the perfect environment for:

• Fungal infections
• Scalp irritation
• Dandruff
• Folliculitis

These conditions can weaken hair roots and contribute to increased shedding if left untreated.