Using Heat and Cold to Reduce Pain
Both heat and cold can help reduce pain. However, it can
be confusing to decide which is more appropriate at any given time. These basic
rules may help:
Use cold for acute pain or a new swollen/inflamed injury.
Use heat for chronic pain or an injury that is a day or more
Ultimately, you need to choose what works best for you.
If icing feels unpleasant, then heat may provide more comfort.
However, it is important to take the type of injury into
account. Different types of injury need different treatments to heal properly.
Ice and heat are not substitutes for medical evaluation and treatment.
Thermotherapy for Pain Relief
Heat is relaxing. That’s why
overworked muscles respond best to heat. Heat stimulates blood flow, relaxes
spasms, and soothes sore muscles.
Heat therapy is also known as thermotherapy.
How It Works
Overworked muscles become sore because of a chemical
called lactic acid. Lactic acid accumulates when the muscles are put under
stress and deprived of oxygen. When there is decreased blood flow to a damaged
area, the lactic acid gets stuck. This build-up creates painful muscle ache. Heat
therapy can help to restore blood flow and speed the removal of lactic acid
When to Use Heat Therapy
Heat is best for treating chronic pain. Chronic
pain is persistent or recurrent pain.
Heat increases blood supply. It stimulates the
elimination of toxins. It also relaxes soreness and stiffness to bring relief.
If you suffer from an ongoing injury, apply heat before exercising.
Applying heat after exercise can aggravate existing pain.
Types of Heat Therapy
There are two types of heat
Local heat is applied to a specific
area with a:
- hot water bottle
- heating pad
- moist heat (hot, damp towel)
- heat wraps
Systemic heat raises your body
temperature with a:
- hot bath
- steam bath
- hot shower
Tips for Applying Heat
- Protect yourself from direct contact
with heating devices.
- Wrap heat sources within a folded towel to
- Stay hydrated during systemic heat
- Avoid prolonged exposure to systemic heat
Cryotherapy for Pain Relief
Generally, ice is used to help
fresh injuries. When your body is injured, the damaged tissue becomes inflamed.
This can cause pain, swelling, or redness.
Swelling is your body’s natural
response to injury. Unfortunately, local swelling tends to compress nearby
tissue leading to pain.
Evidence for using ice to treat pain isn’t as strong as
evidence for using heat. Cold therapy is also called cryotherapy.
How it Works
Ice numbs the injury. The cold narrows blood vessels and
slows down blood flow. This can reduce fluid buildup in the affected area.
Ice is believed to aid in control of inflammation and
swelling. It relieves pain, but does not treat the underlying cause.
When to Use Cold Therapy
Cold is best for acute pain
caused by recent tissue damage (acute inflammation). Ice is used when the injury
is recent, red, inflamed, or sensitive.
Cold therapy can also help relieve any inflammation or
pain that occurs after exercise; this is a form of acute inflammation. However,
unlike heat, you should apply ice after going for a run. Cold
treatment can reduce post-exercise inflammation.
Cold therapy can sometimes also help relieve pain in
Types of Cold Therapy
Cold should only be applied locally.
It should never be used for more than 20 minutes at a time. You can apply cold
- an ice pack
- an ice towel—a damp towel that has been sealed
in plastic and placed in the freezer for about 15 minutes
- an ice massage
- a cold gel pack
- a bag of frozen vegetables
Tips for Applying Cold
- Apply cold immediately after injury or
intense, high-impact exercise.
- Always wrap ice packs in a towel before
applying to an affected area.
- It’s alright to repeatedly ice painful or
swollen tissues. However, you should give your body a break between
- Do not use ice in areas where you have
- Never use ice for more than 20 minutes at a
Excessive use of cold can cause tissue damage.