Millions of people around the world suffer from a self-mutilating and often painful addiction to biting their nails, which can be harder to quit than smoking cigarettes, but is often overlooked as a relatively benign habit.

    Medical experts are now taking a closer look at the addiction and have decided to change its classification from a mere habit to a full-fledged obsessive-compulsive disorder.

    The American Psychiatric Association is preparing to change the designation of nail biting from ‘not otherwise classified,’ to ‘obsessive compulsive disorder’ in its upcoming issue of the Diagnostic and Statistical Manual of Mental Disorders, NBC News reported.

    Habits that are commonly associated with OCD include repetitive hand-washing and hair-pulling. The disease is characterized by unreasonable thoughts and fears that lead to such repetitive behaviors.

    The occasional chewed nail isn’t an indication of the disorder, medical experts assure.

    ‘As with hair pulling and skin picking, nail biting isn't a disorder unless it is impairing, distressing, and meets a certain clinical level of severity,’ Carol Mathews, M.D., a psychiatrist at the University of California, San Francisco, told NBC News.

    ‘That is not the vast majority of nail bitters,’ she said.

    Nail chewing is considered severe when the habit becomes destructive – when it impairs use of the hands or leads to repeated infections.

    Sometimes a nail-biter’s hands and fingers can become infected, but more often, the habit leads to an increased risk of contracting colds and other illnesses because it encourages the spread of germs from the nails to the lips and mouth.

    Nail biters looking to quit their addiction may find they are less inclined to stick their fingers in their mouths if they put lemon juice or hot sauce on their digits.

    Former nail biters who quit the habit said it also helps to wrap nails in tape or Band-Aids and to keep their hands well-manicured.

    全球数百万人爱咬指甲，这嗜好颇为“自残”，有些小痛苦，而且比吸烟还难戒掉，但经常被人们忽视，认为不过是一种相对没什么坏处的习惯。

    医学专家目前正对此进行进一步研究，而且已经决定将其从一种习惯划分到强迫症。

    据美国国家广播公司报道，美国精神病学会正准备在下期《诊断和统计手册》中将“咬甲癖”的名称从“无其他分类”改为“强迫症”。

    与强迫症有关的习惯包括反复洗手和抓头发，通常以过度思考和恐惧而导致重复同一种行为为特点。

    医学专家明确说，偶尔咬指甲不代表患上强迫症。

    美国旧金山加州大学精神病专家、医学博士卡罗-马修斯告诉美国全国广播公司：“和抓头发与抓挠皮肤一样，咬指甲在造成一定的损害，给人带来烦恼，并在临床上达到一定的严重程度时才会划分为强迫症。”

    她说：“而大多数爱咬指甲的人都到不了这个程度。”

    当咬指甲的习惯具有破坏性时，我们才会考虑情况很严重了，也就是当它影响到了手的使用，或者导致反复感染。

    在有些时候，有咬甲癖的人的手和手指会感染，但这种习惯在更多情况下会增加人们患上感冒和其他疾病的风险，因为这增大了细菌从指甲中传染到嘴唇和嘴里的几率。

    想要戒掉咬甲癖的人们可能会发现，如果在手指上涂上柠檬汁或者辣椒酱，就不太会咬指甲了。

    戒掉咬甲癖的人说，在手上缠胶带或者创可贴也很有帮助，要保持精心修正的手型。