Many people carry around hand sanitizer to use whenever they need to clean their hands in a pinch. But for folks with OCD, hand sanitizer can feel like a life raft — sometimes to the point where it becomes an obsession.

"One common obsession with OCD is fear of germs or contamination," counselor Amanda Petrik-Gardner, LCPC, RPT-S, tells Bustle. "Due to this, some may engage in extreme compulsions to decrease the chance of feeling dirty."

That may include using hand sanitizer compulsively throughout the day, she says, or even using other toxic disinfectants to get rid of germs on their body, which can be dangerous and unhealthy.

OCD symptoms often include frequent hand washing and a desire to be clean, due to the fear of contamination. But there's a big difference between washing your hands after using the bathroom or before eating, and the type of aggressive hand washing OCD can lead you to.

"Individuals with an obsession about cleanliness will often engage in ritualistic hand washing, meaning either a certain number of times a day, certain number of times in an instance, or after certain events," Petrik-Gardner says. "This can result in red, dry, chapped hands." And it can be quite painful.

As many as one in four people with OCD are also compulsive hoarders, which means they collect junk and surround themselves with unnecessary things.

"Hoarding disorder is a type of OCD that involves keeping things you don't need to the point that it becomes dangerous or insanitary, or it's harming your relationships," clinical psychologist Aimee Daramus, PsyD, tells Bustle. "Hoarders might save anything, but some will save something specific, like years of nail clippings."

For people who aren't suffering from OCD, or experiencing hoarder tendencies, it's a tough compulsion to understand. But it's still a very real symptom.

"A true hoarder will become really upset and anxious if they have to throw things away, because they're obsessed with the thought that the object might be needed," Dr. Daramus says. The good news is, it is a habit that can be improved upon in therapy.

Some folks with OCD become fixated on numbers, to the point they'll start to seeing a certain numeral everywhere they go — and they may even create rituals or compulsions around it.

Take the number 13, for example. Dr. Daramus has seen cases where people are so fixated on that number that they almost get into car accidents, because they're too busy looking for it on road signs and license plates.

Counting is often shown in movies and TV shows as a funny, quirky side effect of the disorder. But since it can have very real consequences, it's always a good idea to point them out to a therapist.

Similar to the counting compulsion, OCD can make it feel like you have to check and recheck things like door locks — because you can't quite fully believe you locked them properly. And it can become quite time consuming.

"Common habits would be checking non-stop [things like] the stove, the lights, the straighteners/irons, the locks and windows," clinical psychologist Dr. Perpetua Neo, tells Bustle. "You may even abandon an appointment to go home to check [them]."

OCD is often called a doubting disorder, and for good reason. "Other less obvious forms of checking could be checking your emails (that you sent) or going through what you said over and over again, and getting obsessed over your (often, imaginary) mistakes," Dr. Neo says. "If you have a set of rituals that cannot be disrupted, or you have to do them from scratch when they are, it might also be symptomatic of OCD."

Another little-known side effect of OCD is the fear of accidentally harming others, or somehow getting into trouble.

As Dr. Neo says, "Less obvious manifestations of OCD revolve around fears of harming others (or causing harm to others) that you have to do something about it (e.g. by checking or performing some other superstitious ritual) or fears that you are some type of deviant."

For example, if you have this symptom, you might worry that you're causing accidents while driving — even when you aren't. And it can be quite distressing.

Rituals can take any form, which is why some OCD sufferers may find themselves toiling away in the bathroom, performing time-consuming hygiene routines.

For example, when "using the bathroom a person may be compelled to wipe themselves in a distinct manner for a specific number of times," clinical psychotherapist Jeremy A. Montemarano, M.A., LPC, tells Bustle.

While it may sound odd, it makes sense, in a way, to the person with OCD. And even if it doesn't, they feel compelled to do it anyway, as a way of relieving their anxiety.

These things, along with other OCD symptoms, may seem strange. Bu they're nothing to be embarrassed about. Just like feelings of anxiety or depression, they can happen against your will, or feel inexplicable.

And yet, by paying attention to them and recognizing them for what they are — possible signs of OCD — you can reach out for help, and start down the road to feeling better.