 Burns that affect only the superficial skin layers are known as superficial or first @-@ degree burns . They appear red without blisters and pain typically lasts around three days . When the injury extends into some of the underlying skin layer , it is a partial @-@ thickness or second @-@ degree burn . Blisters are frequently present and they are often very painful . Healing can require up to eight weeks and scarring may occur . In a full @-@ thickness or third @-@ degree burn , the injury extends to all layers of the skin . Often there is no pain and the burn area is stiff . Healing typically does not occur on its own . A fourth @-@ degree burn additionally involves injury to deeper tissues , such as muscle , tendons , or bone . The burn is often black and frequently leads to loss of the burned part . 
 Burns <a href='null_relcl' title='1'><mark>that</mark></a>affect only the superficial skin layers are known as superficial or first @-@ degree burns . They appear red without blisters and pain typically <a href='uninflect' title='2'><mark>lasts</mark></a> around three days . When the injury <a href='uninflect' title='3'><mark>extends</mark></a> into some of the underlying skin layer , it <a href='drop_aux' title='4'><mark>is</mark></a>a partial @-@ thickness or second @-@ degree burn . Blisters <a href='drop_aux' title='5'><mark>are</mark></a>frequently present and they <a href='drop_aux' title='6'><mark>are</mark></a>often very painful . Healing can require up to eight weeks and scarring may occur . In a full @-@ thickness or third @-@ degree burn , the injury <a href='uninflect' title='7'><mark>extends</mark></a> to all layers of the skin . Often <a href='dey_it' title='8'><mark>there</mark></a> is no pain and the burn area <a href='drop_aux' title='9'><mark>is</mark></a>stiff . Healing typically <a href='uninflect' title='10'><mark>does</mark></a> not occur on its own . A fourth @-@ degree burn additionally <a href='uninflect' title='11'><mark>involves</mark></a> injury to deeper tissues , such as muscle , tendons , or bone . The burn <a href='drop_aux' title='12'><mark>is</mark></a>often black and frequently <a href='uninflect' title='13'><mark>leads</mark></a> to loss of the burned part . 
Burns affect only da superficial skin layers are known as superficial or first @-@ degree burns . They appear red w/o blisters and pain typically last around three dayz . When the injury extend into some of tdaunderlying skin layer , it a partial @-@ thickness or second @-@ degree burn . Blisters frequently present and they often very painful . Healing can require up to eight weeks and scarring may occur . In a full @-@ thickness or third @-@ degree burn , the injury extend to all layers of the skin . Often it ain't no pain and the burn area stiff . Healing typically do not occur on its own . A fourth @-@ degree burn additionally involve injury to deeper tissues , such as muscle , tendons , or bone . Thdaurn often black and frequently lead to loss of the burned part .