question: Why do unnoticed wounds not hurt?
comment: Wounds that you don't notice don't hurt because they don't hurt enough to be noticed. If you do happen to notice it, it might start hurting as a psychological response to knowing of the wound, as well as from the almost inevitable irritation you'll introduce from checking it out (picking, rubbing, etc.)
passages: The appearance and nature of the wound varies with the type of weapon used and the location of the injury, and may present as a laceration, abrasion, contusion or bone fracture. Where a victim has time to raise hands or arms before being shot by an assailant, the injury may also present as a gunshot wound. Severe laceration of the palmar surface of the hand or partial amputation of fingers may result from the victim grasping the blade of a weapon during an attack. In forensic pathology the presence of defense wounds is highly indicative of homicide and also proves that the victim was, at least initially, conscious and able to offer some resistance during the attack.
   BULLET::::- Foreign bodies. Sharp, small foreign bodies can penetrate the skin leaving little surface wound but causing internal injury and internal bleeding. For a glass foreign body, "frequently, an innocent skin wound disguises the extensive nature of the injuries beneath". First-degree nerve injury requires a few hours to a few weeks to recover. If a foreign body passes by a nerve and causes first-degree nerve injury during entry, then the sensation of the foreign body or pain due to internal wounding may be delayed by a few hours to a few weeks after entry. A sudden increase in pain during the first few weeks of wound healing could be a sign of a recovered nerve reporting internal injuries rather than a newly developed infection.
   Section::::Structure.:Nerve supply.
  
  The cornea is one of the most sensitive tissues of the body, as it is densely innervated with sensory nerve fibres via the ophthalmic division of the trigeminal nerve by way of 70–80 long ciliary nerves. Research suggests the density of pain receptors in the cornea is 300-600 times greater than skin and 20-40 times greater than dental pulp, making any injury to the structure excruciatingly painful.
   The ability to experience pain is essential for protection from injury, and recognition of the presence of injury. Episodic analgesia may occur under special circumstances, such as in the excitement of sport or war: a soldier on the battlefield may feel no pain for many hours from a traumatic amputation or other severe injury.
   On behalf of the Holy Office, Gemelli re-examined Father Pio in 1925, writing a report in April 1926. This time he let Pio show him the wounds. Gemelli saw as its cause the use of a corrosive substance. Pio had attached himself to these wounds. The Jesuit Festa had previously tried to question Gemelli's comments on stigmata in general. Gemelli responded to this criticism in his report and resorted to responding to his knowledge of self-inflicted wounds. He therefore clarified his statements about the nature of Pio's wounds: "Anyone with experience in forensic medicine, and above all in variety by sores and wounds that self-destructive soldiers were presented during the war, can have no doubt that these were wounds of erosion caused by the use of a caustic substance. The base of the sore and its shape are in every way similar to the sores observed in soldiers who procured them with chemical means."
   Wound
  
  A wound is a type of injury which happens relatively quickly in which skin is torn, cut, or punctured (an "open" wound), or where blunt force trauma causes a contusion (a "closed" wound). In pathology, it specifically refers to a sharp injury which damages the Epidermis of the skin.
  
  Section::::Classification.
  
  According to level of contamination, a wound can be classified as:
  
  BULLET::::- Clean wound – made under sterile conditions where there are no organisms present, and the skin is likely to heal without complications.
   The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an involuntary reflex to close the eyelid. Because transparency is of prime importance, the healthy cornea does not have or need blood vessels within it. Instead, oxygen dissolves in tears and then diffuses throughout the cornea to keep it healthy. Similarly, nutrients are transported via diffusion from the tear fluid through the outside surface and the aqueous humour through the inside surface. Nutrients also come via neurotrophins supplied by the nerves of the cornea. In humans, the cornea has a diameter of about 11.5 mm and a thickness of 0.5–0.6 mm in the center and 0.6–0.8 mm at the periphery. Transparency, avascularity, the presence of immature resident immune cells, and immunologic privilege makes the cornea a very special tissue.
   Defense wound
  
  A defense wound or self-defense wound is an injury received by the victim of an attack while trying to defend against the assailant. Defensive wounds are often found on the hands and forearms, where the victim has raised them to protect the head and face or to fend off an assault, but may also be present on the feet and legs where a victim attempts defense while lying down and kicking out at the assailant.
   The wounds were examined by Luigi Romanelli, chief physician of the City Hospital of Barletta, for about one year. The physician Angelo Maria Merla noted that the wounds were not tubercular in origin but could not make an official diagnosis without further tests. The surgeon Giorgio Festa, a private practitioner, also examined them in 1920 and 1925. Professor Giuseppe Bastianelli, physician to Pope Benedict XV, examined the wounds, but no report of his examinations was made. Pathologist Amico Bignami of the University of Rome also observed the wounds describing them as shallow. Festa who had originally agreed with Bignami later described the wounds as superficial when covered with a scab.
   Little Wound was present at the battle of Massacre Canyon on August 5, 1873, in Hitchcock County, Nebraska. It was one of the last battles between the Pawnee and the Sioux and the last large scale battle between Native American tribes in the area of the present day United States of America.
   How are the electric fields at a wound produced? Epithelia actively pump and differentially segregate ions. In the cornea epithelium, for example, Na+ and K+ are transported inwards from tear fluid to extracellular fluid, and Cl− is transported out of the extracellular fluid into the tear fluid. The epithelial cells are connected by tight junctions, forming the major electrical resistive barrier, and thus establishing an electrical gradient across the epithelium – the transepithelial potential (TEP). Breaking the epithelial barrier, as occurs in any wounds, creates a hole that breaches the high electrical resistance established by the tight junctions in the epithelial sheet, short-circuiting the epithelium locally. The TEP therefore drops to zero at the wound. However, normal ion transport continues in unwounded epithelial cells beyond the wound edge (typically 1 mm away), driving positive charge flow out of the wound and establishing a steady, laterally-oriented electric field (EF) with the cathode at the wound. Skin also generates a TEP, and when a skin wound is made, similar wound electric currents and fields arise, until the epithelial barrier function recovers to terminate the short-circuit at the wound. When wound electric fields are manipulated with pharmacological agents that either stimulate or inhibit transport of ions, the wound electric fields also increase or decrease, respectively. Wound healing can be speed up or slowed down accordingly in cornea wounds.
   Insensitivity to pain may also result from abnormalities in the nervous system. This is usually the result of acquired damage to the nerves, such as spinal cord injury, diabetes mellitus (diabetic neuropathy), or leprosy in countries where that disease is prevalent. These individuals are at risk of tissue damage and infection due to undiscovered injuries. People with diabetes-related nerve damage, for instance, sustain poorly-healing foot ulcers as a result of decreased sensation.
   Peripheral injuries trigger complex changes in the central nociceptive system which can lead to central sensitization that enhances the sensitivity and responsiveness of the brain regions involved in sensory processing. In some cases, these physiological responses progress to neuropathic centralized pain.
  
  Section::::Treatments.
   According to Amnesty International, who interviewed military experts and a forensic pathologist, "many of the wounds observed by doctors in Gaza are consistent with those caused by high-velocity Israeli-manufactured Tavor rifles using 5.56mm military ammunition. Other wounds bear the hallmarks of US-manufactured M24 Remington sniper rifles shooting 7.62mm hunting ammunition, which expand and mushroom inside the body. The nature of these injuries shows that Israeli soldiers are using high-velocity military weapons designed to cause maximum harm to Palestinian protesters who do not pose an imminent threat to them."
  
  Section::::Casualties.:Killing of medical personnel.
   The healing corneal wounds consist of newly abutting corneal stroma, fibroblastic cells, and irregular fibrous connective tissue. Closer to the wound surface lies the epithelial plug, a bed of the cells that form the normal corneal epithelium which have fallen into the wound. Often this plug is three to four times as deep as the normal corneal epithelium layer. As the cells migrate from the depth of the plug up to the surface, some die before reaching it, forming breaches in the otherwise healthy epithelial layer. This, consequently, leaves the cornea more susceptible to infections. The risk is estimated to be between 0.25% and 0.7% Healing of the RK incisions is very slow and unpredictable, often incomplete even years after surgery. Similarly, infection of these chronic wounds can also occur years after surgery, with 53% of ocular infections being late in onset. The pathogen most commonly involved in such infections is the highly virulent bacterium "Pseudomonas aeruginosa".
   Experiments looking at the WDR neurons in animals have shown that a strong tactile stimulus in the peripheral inhibitory field could reduce the response to a painful stimulus to the same extent as a weak tactile stimulus closer to the centre of the receptive field.
  
  These data show the Gate Control Theory of Pain was correct in the prediction that activation of large tactile afferent fibres inhibit the nociceptive afferent signal being transmitted to the brain.
  
  Section::::Interactions between touch and pain.
   As the body comes into contact with an electrical source, it becomes part of the electrical circuit. As such, the current has a point of entry and an exit at two different points on the body. The point of entry tends to be depressed and leathery whereas the exit wound is typically more extensive and explosive. It is hard to accurately diagnose an electrical burn because only the entry and exit wounds are visible and the internal damage is not.
  
  Section::::Prevention.
  
  Section::::Prevention.:Basic electrical safety.
   When the general visceral sensory fiber is simulated, the central nervous system does not clearly discern whether the pain is coming from the body wall or from the viscera, so it perceives the pain as coming from somewhere on the body wall, e.g. left arm/hand pain, jaw pain.
  
  So the pain is "referred to" the related dermatomes of the same spinal segment.
   Ruffini corpuscles respond to sustained pressure and show very little adaptation.
  
  Ruffinian endings are located in the deep layers of the skin, and register mechanical deformation within joints, more specifically angle change, with a specificity of up to 2.75 degrees, as well as continuous pressure states. They also act as thermoreceptors that respond for a long time, so in case of deep burn there will be pain, as these receptors will be burned off.
   In July/August 2006, doctors in the Gaza Strip reported unusual wounds caused by Israel Defense Forces attacks against Palestinians, claiming that they were from previously unknown weapons. A lab analysis of the metals found in the victims' bodies was reportedly "compatible with the hypothesis" that DIME weapons were involved. Israel denied possessing or using such weapons, and an Israeli military expert said that the wounds were consistent with ordinary explosives.
   The pathologist Amico Bignami conducted a medical examination of Father Pio's wounds in 1919 and concluded that it was a skin necrosis that was hindered from healing by chemicals such as iodine tincture. 
  
  Section::::Investigations of Pater Pio by medical and church authorities.:Giorgio Festa, medical examinations 1919 and 1920.
   In prisons and forced labour camps people sometimes self-injure so that they will not be forced to work and could spend some time in the more comfortable conditions of the infirmary barracks.
  
  Section::::Types of wounds.
  
  Among the most common type of wounds are a rifle shot to the hand, arm, leg, or foot.
  
  Wounds can also occur by deliberate neglect of health, e.g. by failing to treat a minor wound that will become infected, or "forgetting" foot care in damp conditions that lead to fungal infections.
  
  Section::::Punishments.
   Section::::Management.:Cleaning.
  
  Evidence to support the cleaning of wounds before closure is scant. For simple lacerations, cleaning can be accomplished using a number of different solutions, including tap water and sterile saline solution. Infection rates may be lower with the use of tap water in regions where water quality is high. Cleaning of a wound is also known as 'wound toilet'.
  
  Section::::Management.:Closure.
   The somatosensory system includes multiple types of sensations from the body. This includes light, touch, pain, pressure, temperature, and joint /muscle sense. Each of these are categorized in three different areas: discriminative touch, pain and temperature, and proprioception. Discriminative touch includes touch, pressure, being able to recognize vibrations, etc. Pain and temperature includes the perception of pain/ amounts of pain and the severity of temperatures. The pain and temperature category of sensations also includes itching and tickling. Proprioception includes receptors for everything that occurs below the surface of the skin. This includes sensations on various muscles, joints, and tendons. Each of these three categories have their own types of pathways and receptors. These pathways target the cerebellum in the brain. This section of the brain tracks what the muscles are doing at all times so any potential damage to this area can greatly affect one's senses.
   If a person presents to a healthcare center within 6 hours of a laceration they are typically closed immediately after evaluating and cleaning the wound. After this point in time, however, there is a theoretical concern of increased risks of infection if closed immediately. Thus some healthcare providers may delay closure while others may be willing to immediately close up to 24 hours after the injury. Using clean non-sterile gloves is equivalent to using sterile gloves during wound closure.
  
raw_presuppositions: Unnoticeable wounds should hurt.  Wounds that hurt can go unnoticed.
raw_corrections: Unnoticeable wounds don't hurt because they are so miniscule to the point which makes them unnoticeable to begin with.  If your wound hurts, then you will notice that it hurts.