1. Physical Health
Having to commute to a job guarantees a minimum amount of exercise. Working from home does not. You can easily have days go by where you never leave the house. This could be because you are swamped with work or responding to alerts, or any number of things. Since you are working alone you don't get those natural little bits of physical activity from office life - going for a walk with a manager, grabbing lunch with someone, walking over to a colleague's desk to ask a questions, etc. You have to make a conscious effort to get out daily and do something. This can be harder than you think if you're an introvert. You may have several days where there is really just no need. So you need to get a good routine in place lest you end up putting on weight.
2. Mental Health
Some people are antisocial. For them the isolation of remote work is a feature not a bug. I found this true for myself to some extent. I genuinely like being alone when I can. However over the long term, working remotely will blunt your social skills. Whether or not you consider your coworkers friends, the daily close proximity I think is helpful to most people if only because it keeps them practiced in manners and social cues. In the worst case scenario the isolation of remote work can exacerbate other mental health issues - everything from minor neuroses to depression. When you are around other people there is at least the chance that someone might notice if there is something wrong with you.
Having an active social life outside of work hours can mitigate much of this. That will at least help you to avoid the sense of loneliness that can sneak up on remote workers. The trouble is that even if you keep busy outside of work, you are still missing out on an important category of socialization - professional interactions in a work environment. I experienced this firsthand after a long stretch of working remotely and then attending a company conference. It was really jarring. I recall feeling very anxious and being really awkward around everyone. After enough time passes you sort of forget how to act in an in-person team meeting, or business conference.
3. Work Habits
What's the old quote? There are lies, damn lies, and working from home. It is true that working from home requires more accountability. The office environment at least offers peer pressure. Every now and then someone might look at your screen and catch you on reddit. If you are slacking you might notice it in people's body language and eye contact. You can feel the atmosphere and detect a lot of nonverbal cues. When you're on your own at home, you have to hope that your manager is giving you sufficient feedback and that your JIRA ticket record speaks for itself. Unfortunately I think it is human nature to take advantage sometimes - to squeeze in an errand or some Dark Souls PVP because why not? I've got two monitors and extra time. Who's going to know? There exceptions to this issue of course. Some people do their best work from home. Still it's something to keep in mind.
5. Career Progression
This one can sneak up on you. In a company where most of the employees are on-site and a handful are remote, it is easy for the latter workers to be overlooked when promotion time rolls around. It is a natural human bias to have more trust and concern for people that are physically present. Sure, Andy out in Toronto pushed some great features last quarter. But he wasn't out drinking with me until 1 am like Tim. I haven't been able to shoot the shit with him in the break room like with Mike. I don't actually see him with that determined look in his eye at his desk 10 hours a day reviewing code like I do with Sarah.
No matter how great Andy is, he just can't leave the same type of impression as the people that are there. I have seen some orgs where it is implicitly understood that off-site guys are not to be considered for leadership roles. Sometimes it is explicit, as happened with Yahoo and their crackdown on remote work. This issue is the hardest to solve because ultimately it is out of your hands as an individual. It is up to your company to have a strong remote work culture that puts off-site people on an equal footing. That doesn't just happen - it takes effort and entails a cost to the company. Most will not incur that cost if they do not see the benefit.
The point of this post is not to trash the concept of remote work. I think remote work is extremely important for the future of the global economy and all developed societies. It is critical that we have more flexible work arrangements, particularly for parents with small children and talented people with other unique situations that make on-site work difficult.
However there are pitfalls to consider. It's not as simple as having a wacky Slack chatbot. All of the issues I bring up in this article are solvable. The problem is that the solutions often take carefully planned deliberate efforts. People are not always capable of this. Thus you have to look at the real human toll of long-term remote work arrangements and find ways to mitigate the negatives. Remote workers need to be mindful of the physical and psychological effects over the long term. Companies need to be honest about how remote work can influence career progression.
Like anything else people need to consider the tradeoffs. Remote jobs can be a godsend or a curse depending on your situation.