Let it be Nick Jonas or I, we all at some point have experienced that suffocating feeling; jealousy. It is an emotion that is frowned upon, however scientifically proven it’s a natural tendency in every human. The more in tune you are with your emotions, the more you’ll feel jealous in comparison to others. Gender is hardly a factor that influences it. Envy is different from jealousy. Jealousy is the result of feelings of insecurity, fear, concern and anxiety. Jealousy is a complex emotion that encompasses many different kinds of feelings ranging from fear of abandonment to rage and humiliation.
To understand it better it’s categorized into two types; normal and abnormal. Sibling rivalry, adolescent jealousy, work or power jealousy and romantic jealousy are normal.
Abnormal jealousy is morbid, psychotic, pathological, delusional or anxious jealousy. Being jealous in instances where a person perceives a threat to the relationship when there’s no threat present, then that is considered as abnormal.
The extreme version of jealousy is the hallmark of various ill psychological conditions like paranoia or schizophrenia, or a chemical imbalance in the brain.
Tripped out fact: Even wild animals like chimpanzees and elephants exhibit jealous tendencies.
Normal jealousy has the simplest remedy but has been proven to be difficult in application. It is being honest about your feelings with your own self first then with others, who are involved in it.
Abnormal jealousy needs serious attention and ought to be treated with therapy or there’s a possibility of going bonkers and making others around you go bonkers.
Image Sources: 
Understand jealousy on different levels http://web.csulb.edu/~psych/deptinfo/faculty/hupka/papers.htm