im really worried about something?

i was reading someone elses question and someone posted these symptoms of being underweight and i have a alot of them: what should i do??

these were the symptoms:
Physical

* Stunted growth
* Endocrine disorder, leading to cessation of periods in girls (amenorrhoea)
* Decreased libido; impotence in males
* Starvation symptoms, such as reduced metabolism, slow heart rate (bradycardia), hypotension, hypothermia and anemia
* Abnormalities of mineral and electrolyte levels in the body
* Thinning of the hair (makes your hair look weird and ugly)
* Growth of lanugo hair over the body
* Constantly feeling "cold"
* Zinc deficiency
* Reduction in white blood cell count
* Reduced immune system function (increases chance of getting several diseases, usually harmless diseases like flue may put your health at risk)
* Pallid complexion and sunken eyes
* Creaking joints and bones
* Collection of fluid in ankles during the day and around eyes during the night
* Tooth decay
* Constipation
* Dry skin
* Dry or chapped lips
* Poor circulation, resulting in common attacks of ‘pins and needles’ and purple extremities
* In cases of extreme weight loss, there can be nerve deterioration, leading to difficulty in moving the feet
* Headaches
* Brittle fingernails
* Bruising easily

Psychological

* Distorted body image
* Poor insight
* Self-evaluation largely, or even exclusively, in terms of their shape and weight
* Pre-occupation or obsessive thoughts about food and weight
* Perfectionism
* Obsessive compulsive disorder (OCD)
* Belief that control over food/body is synonymous with being in control of one’s life
* Refusal to accept that one’s weight is dangerously low even when it could be deadly
* Refusal to accept that one’s weight is normal, or healthy

Emotional

* Low self-esteem and self-efficacy
* Intense fear about becoming overweight
* Clinical depression or chronically low mood
* Mood swings

Some of these causes of being underweight may sometimes not occur before you get older. Like for example bone problems.

Other causes are loss of menstruation, risk of becoming sterile, stomach pain, delayed/abnormal puberty and wounds will also heal slower, and easier get infected, due to a weak immune system.