It is bad for you physically.

Heart problems are not uncommon for people that put in too many hours at work. A study,[3] released that long working hours may cause raised blood pressure, unhealthy diet, and stress. A combination of these may cause serious health problems.The researchers put together various results from studies and came up with a conclusion that working too long hours in the office resulted in a 40 to 80 percent greater chance of heart disease compared to a regular 8-hour work day.

It makes you depressed.

Employees that work long hours are at a risk for depression. In a new study,[4] it was revealed that employees who work over 11 hours in a day have at least a double risk of a major depressive episode than employees who work the regular 7-8 hours in a day.

It affects you mentally and cognitively.

Someone that works long hours has a tendency to be less productive. This is because employees that work more than the regular 8-hour workday have a tendency to have cognitive issues. A study[5] had found out that participants that worked more than 55 hours per week had lower scores on vocabulary tests than those that worked 40 hours or less in a week. There was also a major drop in the particiants’ fluid intelligence in between the tests.

What you should do

Do use your vacation days and avoid working more than the regular 8 hours in a day. The negative effect of overworking could greatly hinder your productivity and in turn affect your work in general. If it affects your work, then it affects the productivity of the company too. A Stanford University study[6] found that employee output goes down after 50 hours per week and dives down even more after 56 hours. Similar studies have found that there is a relation between overwork and absenteeism, impaired decision-making skills and long-term memory loss.In a separate report from the US-based campaign Project: Time Off[7] found out that long-working office martyrs were less likely than their peers to have received a bonus in the last three years. After all, which company would give a bonus to an employee that is always absent because of sickness, always mentally and physically tired, and not productive? Overall if you limit your work week to 40 hours you will be more done and be physically and mentally healthy.