Burns are injuries caused by thermal, chemical, electrical, radiation or other energy exposure that damages skin and potentially deeper tissues. Thermal burns are commonly produced by hot liquids, flames, hot surfaces or steam, while chemical burns result from corrosive substances and electrical injuries arise when electrical energy passes through tissue. Burn severity depends on energy intensity, duration of exposure, affected surface area, tissue depth, anatomical site and associated injuries. Skin damage ranges from superficial injury with preserved deeper structures to full-thickness destruction extending through the skin into subcutaneous tissue or deeper anatomical structures. Burns can therefore represent anything from a limited local injury to a major systemic physiological insult requiring specialist care.
Burn depth is clinically important because it influences pain, appearance, healing potential and treatment. Superficial burns involve the epidermis and typically produce erythema and pain without destruction of the full skin thickness. Partial-thickness burns extend into the dermis and may be blistered, moist and painful, with deeper partial-thickness injuries having less viable tissue and a greater tendency towards delayed healing and scarring.
Full-thickness burns destroy the entire epidermis and dermis and may appear pale, leathery, brown or charred; sensation can be reduced because sensory nerve endings have been destroyed. Depth can evolve after the initial injury because impaired perfusion, inflammation and secondary tissue damage may convert marginally viable tissue into deeper necrosis.
Burn extent is commonly estimated using the percentage of total body surface area involved, with different assessment methods appropriate for adults and children. The distribution of the burn matters as much as surface area because injuries involving the face, hands, feet, major joints, genital region or airway can have serious functional consequences even when the total area is comparatively small.
Circumferential burns around limbs or the chest can impair circulation or respiratory mechanics because damaged tissue may become constrictive as swelling develops. Inhalation injury can result from exposure to smoke, hot gases or toxic combustion products and can threaten the airway or cause pulmonary complications. Burn assessment therefore extends beyond visible skin damage.
Major Burns trigger systemic physiological responses. Extensive tissue injury can cause increased capillary permeability, fluid movement from the circulation into tissues and substantial fluid losses from the damaged surface. Severe burns can consequently produce hypovolaemia, impaired organ perfusion and shock if not appropriately managed. The inflammatory response can become widespread, increasing metabolic demands and contributing to profound catabolism. Large burns also disrupt the skin's barrier function, increasing heat loss and susceptibility to microbial invasion. These physiological effects explain why management of extensive burns requires attention to circulation, temperature, fluid balance, airway function, infection prevention, nutrition and other systemic considerations rather than treating the visible wound alone.
Initial Burn care prioritises stopping the burning process and assessing immediate threats to life. Appropriate first aid for many thermal burns includes cooling the affected area with cool running water for a sustained period, while avoiding ice or extremely cold materials that can worsen tissue injury. Clothing or jewellery that is not stuck to the skin can generally be removed to limit ongoing heat exposure and accommodate swelling.
Chemical burns require prompt removal of the contaminating substance and careful irrigation appropriate to the chemical involved, while electrical injuries require consideration of hidden internal damage and cardiac effects. Major burns, suspected inhalation injury, extensive chemical or electrical burns and burns involving critical anatomical areas require urgent professional assessment.
Infection is an important complication because the normal cutaneous barrier is disrupted. However, redness and inflammation immediately surrounding a burn do not automatically indicate infection because they can be part of normal injury responses. Increasing pain, spreading erythema, purulent drainage, systemic deterioration or other clinical changes may raise concern for infection and require assessment. Healing depends on remaining viable tissue, wound depth, perfusion, infection control and appropriate wound management. Burns that fail to heal within an appropriate timeframe have greater risk of hypertrophic scarring and functional restriction, particularly across joints. Specialist burn services may use advanced dressings, surgery, grafting, rehabilitation and scar-management strategies according to injury severity.
Burn complications can occur during both acute treatment and long-term recovery. Early complications include shock, airway compromise, hypothermia, electrolyte abnormalities, acute kidney injury and infection, depending on severity. Later consequences can include hypertrophic scars, contractures, altered pigmentation, chronic itching, pain, reduced mobility and psychological or social effects associated with visible injury. Contractures are particularly important when scars cross joints because shortening of the scarred tissue can restrict movement. Rehabilitation may involve physiotherapy, occupational therapy, positioning, splinting and scar management. The recovery process can therefore continue for months or years after the initial wound has closed.
Burn prevention depends on reducing exposure to heat, corrosive substances, electricity and radiation and on controlling environmental hazards. Safe handling and storage of hot liquids, cooking equipment, chemicals and electrical devices can reduce risk, while smoke alarms and appropriate fire-safety measures can reduce fire-related injury. Children are particularly vulnerable to scalds because of their smaller body size and different exposure patterns.
A common misconception is that all burns should be treated with household substances such as butter, oils or creams immediately after injury; such substances can interfere with assessment and are not substitutes for appropriate cooling and medical evaluation. Burn management is fundamentally determined by mechanism, depth, extent, anatomical location and systemic effects.
