We are often asked,
“Which one is better, ice pack or heating pad?”
To decide which one of them is more suitable to the condition, we must understand how each of them works to reduce pain.

Cryotherapy In acute trauma or injury, the smallest blood carrying arteries or veins start leaking out fluid. Amount of fluid leaked out into extravascular space depends on the severity of injury and how fast the fluid is rushing through blood vessels. As a body’s reaction to cold,cold packs temporarily decrease the diameter of blood vessels locally. Hence reduce leaking of fluid and reduce swelling. This leaking out of fluid if persists, causes swelling up of the local area of injury causing compression of local blood vessels and reducing blood flow, impairing healing in long term.

Heat therapy Heat therapy, also called thermotherapy, is the use of heat as an adjunct to physiotherapy treatment for pain relief. Heat therapy works in exactly opposite way. It increases the diameter of blood carrying vessels and hence the blood flow to the area of application. This increased blood flow helps in washing away the accumulated lactic acid in a particular part of the body. Heat is also comforting for most people, enhancing its analgesic properties.

Heat therapy.

  • Promotes blood flow.
  • Reduces muscle spasm.
  • Helps muscles relax.

Returning to our previous question,
When should we apply heat and when is cold pack more effective?

Acute Injury- Cryotherapy is most effective when used within 24-48 hrs of injury. It reduces swelling, inflammation and helps in reduction of pain.

Chronic pain- In 2006, a team of researchers found that patients with lower back pain who exercised and use continuous low-level heat wrap therapy (CLHT) experienced less pain than those who did not use CLHT.

Previous studies had shown that, for some people, CLHT relieved pain more effectively than oral analgesics, acetaminophen, and ibuprofen.

However, the effectiveness of heat treatment may depend on the depth of the tissue affected by the pain or injury.
The decision of using a hot or cold pack is usually taken on clinical symptoms associated with the condition. Your physiotherapist might use other electrotherapeutic modalities like ultrasound or Laser to gain additional benefits along with those of heat therapy.