Although most who gamble do so without harm, approximately 6 million American adults are addicted to gambling.Signs of a gambling problem include:
Using income or savings to gamble while letting bills go unpaid
Repeated unsuccessful attempts to stop gambling
Chasing losses
Losing sleep over thoughts of gambling
Arguing with friends or family about gambling behavior
Feeling depressed or suicidal because of gambling losses

Oceania (Australia)
Casinos and poker machines in pubs and clubs facilitate problem gambling in Australia. The building of new hotels and casinos has been described as "one of the most active construction markets in Australia"; for example, AUD$860 million was allocated to rebuild and expand the Star Complex in Sydney.A 2010 study, conducted in the Northern Territory by researchers from the Australian National University (ANU) and Southern Cross University (SCU), found that the proximity of a persons residence to a gambling venue is significant in terms of prevalence. Harmful gambling in the study was prevalent among those living within 100 metres of any gambling venue, and was over 50% higher than among those living ten kilometres from a venue. The studys data stated:

Specifically, people who lived 100 metres from their favourite venue visited an estimated average of 3.4 times per month. This compared to an average of 2.8 times per month for people living one kilometre away, and 2.2 times per month for people living ten kilometres away. According to the Productivity Commissions 2016 report into gambling, 0.5% to 1% (80,000 to 160,000) of the Australian adult population had significant problems resulting from gambling.
In order to be diagnosed, an individual must have at least four of the following symptoms in a 12-month period:
Needs to gamble with increasing amounts of money in order to achieve the desired excitement
Is restless or irritable when attempting to cut down or stop gambling
Has made repeated unsuccessful efforts to control, cut back, or stop gambling
Is often preoccupied with gambling (e.g., having persistent thoughts of reliving past gambling experiences, handicapping or planning the next venture, thinking of ways to get money with which to gamble)
Often gambles when feeling distressed (e.g., helpless, guilty, anxious, depressed)
After losing money gambling, often returns another day to get even ("chasing" ones losses)
Lies to conceal the extent of involvement with gambling
Has jeopardized or lost a significant relationship, job, education, or career opportunity because of gambling
Relies on others to provide money to relieve desperate financial situations caused by gambling

Factors that lead to gambling addiction
Mayo Clinic specialists state that compulsive gambling may be result from biological, genetic, and environmental factors, such as:
mental health disorders (the presence of substance use disorders, personality disorders, emotional states)
age and sex (usually found in youth or middle-aged people, and more common to men than women)
impact on family or friends
personality traits
drugs with rare side-effects (for example, antipsychotic medications or dopamine agonists).Other studies add the following triggers to the mentioned above:
traumatic conditions
job-related stress
solitude
other addictionsIf not treated, problem gambling may cause very serious and lasting effects on an individuals life:
relationship related issues
problems with money, bankruptcy
legal problems, imprisonment
health problems
suicide, including suicidal thoughts and attempts

Suicide rates
A gambler who does not receive treatment for pathological gambling when in a desperation phase may contemplate suicide.