Valentine’s Day is the perfect opportunity to let someone know that you’re interested in a romantic relationship. It’s also traditionally the day to shower your significant other with attention. These practices go back hundreds of years and the tradition has become a mainstay from childhood classrooms to the retirement home.

Love and romance are the most talked about, written about, and thought about of the human emotions. Fear may get your heart racing and envy may make you sad or frustrated. Love and feelings of love are the only emotion that so fully invigorates all of our senses. There’s a reason that love affects you all over in such an intense way and that all starts in your brain.

Top 5 Ways Love Affects Your Brain

If you’ve ever wondered what love and romance are on a scientific, logical level, it all starts in the brain. Your heart is probably the organ most associated with emotion, but your thoughts and the areas that recognize love are housed inside your head. As hard as it may be to define love, we know scientifically that it exists because we can see the affects it has on the person who feels that emotion.

Love extends beyond initial feelings associated with seeing a person that we find enticing. We know that people feel intense love and attraction during times when their hormone levels are highest. This is likely a reaction built into our brain to help our species procreate. People are more propelled to look for and find mates during times when their estrogen and testosterone are higher. This is a biological response that doesn’t differ much from humans to the animal kingdom.

On a deep level, our bodies understand when someone might be an appropriate mate which does have something to do with the attraction. This is one of the theories behind pheromone perfumes and using pheromones to attract a mate. While science still hasn’t confirmed the use of pheromones, there are definite changes in the brain that accompany love.

Top 5 Affects Love Has on Your Brain

Being in love can do a lot of interesting things to your thought process. That person is always on your mind. You might hear songs that always remind you of them. You may be more apt to daydream and being around them probably makes you smile more and exhibit other outward signs of infatuation.

Some of these outward signs are really just symptoms associated with very interesting changes being activated in your brain, like the following:

1. Love Increases the Release of Dopamine. Dopamine is the feel good chemical found in the areas of your brain that control pleasure. In studies as far back as 2005, we’ve seen evidence that people have increased activity in these regions of the brain when they view pictures or are discussing people who they’re in a romantic relationship with. This release is what gives you that heightened sense of happiness when you see the person you’re in love with. The areas which are most responsive are pleasure centers often associated with things like sex, food, and even drug or alcohol use.

2. Norepinephrine Increases with Feelings of Love. Norepinephrine works in concert with dopamine. This chemical is often responsible for the anxiety or uneasy feeling involved in a relationship. Symptoms like the inability to sleep or eat might stem from this chemical. It’s also the reason that you may be more apt to act impulsively.

3. Love May Decrease Serotonin. Many studies currently suggest that someone in love may show decreased levels of serotonin. Taken to an unhealthy level with a person who has other addictive traits, the loss of serotonin may not be entirely positive. It is a common side effect for those who report to being in a new or serious relationship.

4. Oxytocin Is Released. The first three chemicals mentioned can be released at any time during the initial phase of an attraction. Oxytocin, however, is associated with a deeper level of caring and commitment. You may have heard of oxytocin being released when you hug or snuggle someone. This hormone is also released during childbirth, breastfeeding, and during orgasm. If you consider these activities together, you’ll notice that each is intended to bring the people involved together or help in bonding. Breastfeeding is when the mother and child develop their deeper attachment. Sex often helps relationships bond in a deeper and more lasting way. In a relationship, oxytocin is released to help your natural bonding process. The hormone promotes feelings of contentment and security.

5. The Hormone Vasopressin Is Released. Vasopressin is released at the same time as oxytocin and is also related to childbirth and breastfeeding. It can be stimulated by skin on skin contact and is released during orgasm, as well. Like oxytocin, this hormone is linked to permanent or lasting bonding. Vasopressin is present in long-lasting commitments.

How Your Brain Processes Love

Each of the five hormones mentioned above have some part in any romantic or love relationship. For single people, the good news is that many close friendships can also spur the release of essential chemicals for mental health, such as dopamine. If you’re wondering why these feelings of euphoria and excitement don’t stay throughout the entire relationship, there’s a reason for that, too.

Often the first three chemical reactions are only extremely active during the initial attraction phase. In that “honeymoon” phase of a relationship, those chemicals lead you further into the attachment and will also subdue other areas of the brain. For instance, the areas of the brain that are responsible for assessing a situation without bias and making assessments are often under performing. This is why people who are building an attachment to a love partner often don’t see the faults that are easily apparent to everyone else.

Once you’ve moved past this initial phase to the part of the relationship where you’re forming long-lasting bonds, you’re more able to see things with greater clarity.