How to Know When You're in Love

Medically Reviewed by Jabeen Begum, MD on November 07, 2022
5 min read

“When you know, you know.” When you hear someone say that, you know they’re talking about love — but they don't explain how you know. Some say love is when you care about someone more than yourself. Others insist it’s the realization that you’ve found your soulmate. The truth is that falling in love usually happens so fast that there’s not much time to analyze. 

Luckily, humans have been fascinated by the concept of romantic love for thousands of years. They’ve written books, established theories, and conducted studies. This both saves you a lot of legwork and means there are effective ways to determine whether you’re in love or simply infatuated.

Robert Sternberg’s triangular theory of love proposes that there are three primary components of love:

  • Intimacy. This refers to the close bond and feeling of connectedness between two people in a loving relationship.
  • Passion. Many people focus on passion when defining romantic love, and it does play a crucial part. Passion fuels physical attraction, romance, and sexual activity.
  • Decision/commitment. This is the part where you decide you love someone — and, later, commit to continue loving that person in a long-term relationship.

The intensity of love varies depending on how strongly you feel each of the above components, and this intensity will determine which of the eight different types of love you might experience.

According to this theory, the eight types of love are as follows: nonlove, liking, infatuation, empty love, romantic love, companionate love, fatuous love, and consummate love. Consummate love is what you might call “true love,” and you can only achieve it when you feel all three components of love simultaneously.

A relationship isn’t limited to one type of love. In fact, you may find that you experience multiple kinds of love throughout the duration of one relationship.

Psychologist Elaine Hatfield offered some insight regarding the difference between love and infatuation. She proposed that there are two types of love: passionate love and companionate love.

Infatuation is a driving force behind the passionate love. This powerful emotional state revolves around intense longing, sexual desire, and excitement. Passionate love is the type of love you usually see in movies. 

Ideally, passionate love will evolve into companionate love. Companionate love is a state of attachment that’s ruled by less intense emotion. Born of attachment, intimacy, and commitment, companionate love is defined by feelings of affection and tenderness for someone you trust. While passionate love tends to have a shorter shelf life and rarely lasts longer than two years, companionate love is an enduring type of love with the potential to increase over time.

To summarize: If you’re overwhelmed by anticipation and attraction, you’re probably infatuated. If your so-called “butterflies” have transformed into feelings of tenderness, trust, and genuine concern for your partner’s well-being, you just might be in love.

When you’re falling in love, it feels all-consuming because it is. Being in love causes your brain to release powerful chemicals that impact your body, mind, and ability to stop daydreaming about the object of your affection. The levels and combinations of these chemicals vary depending on the stage of love you’re in.

  • Lust creates a flood of testosterone and estrogen.
  • Attraction alters your levels of dopamine, norepinephrine, and serotonin.
  • Attachment triggers the release of oxytocin and vasopressin.

While the above aspects of love are closely related, they don’t always occur at the same time. When all three do combine, you’re almost certainly in love.

Here’s what happens to your brain when you're in love:

  • Your brain partially shuts down. Lust and attraction actually shut down the prefrontal cortex of your brain, which helps you make rational decisions. After all, lust has no need for logic — testosterone and estrogen are secreted by the testes and ovaries, and lust relies on those sex hormones to raise your libido.
  • You produce less serotonin. Lower serotonin levels are thought to be responsible for that “I’m obsessed with you” feeling during the early stages of infatuation and are also associated with obsessive-compulsive behavior.
  • Your brain brews a powerful chemical cocktail. Overactive sex hormones aren’t the only forces at work when you’re falling in love. The hypothalamus is a region of your brain that controls emotion and is responsible for releasing all that dopamine, oxytocin, and vasopressin. Dopamine makes you feel euphoric and giddy, oxytocin (also known as the “love hormone”) triggers your bonding instincts, and vasopressin sparks the desire to protect your partner. These chemicals all contribute to the benefits of falling in love, including that head-over-heels feeling.
  • The reward center goes into overdrive. Brain scans have shown that the primary reward centers of the brain fire excessively when someone sees a photograph of a person they find very attractive, so you can imagine how that might escalate when attraction combines with love.

When your brain undergoes the above changes, it influences what happens to your body when you're in love.

  • No rest for the lovestruck. Love (and, more specifically, norepinephrine) actually can keep you up at night. It can also contribute to general restlessness and decreased appetite.
  • Is it hot in here? One study found that being around a loved one can raise your internal body temperature, which explains why seeing your love interest can make you blush. While mapping the effects of emotion-triggered bodily sensations, another study found that love increased activity throughout the entire body.
  • Be still, beating heart. In the initial stages of infatuation, you might notice your heart beating extra-fast. It’s not your imagination — being in love really can raise your heart rate.
  • Breathe it in. If you love someone, you may find their scent intoxicating. It turns out, their scent (i.e., pheromones) may be what attracted you in the first place.

If you’re in love, you’re in luck. Being in love can contribute to longer life, a healthier heart, and decreased stress. Plus, it’s hard to top the exhilaration that accompanies the earlier stages of romance.

The many positive effects of love can feel addictive. But is love actually an addiction?

As discussed above, higher levels of dopamine combined with lower levels of serotonin can trigger obsessive thinking — and falling in love is, in fact, an obsession. It’s not uncommon to wonder whether you’re addicted to your love interest.

There are chemical similarities between love and addiction, and brain imaging has shown that the brain activity of people in love does resemble the brain activity of people battling addiction. For instance, both love and cocaine addiction seem to cause increased activity in the nucleus accumbens.

However, love is classified as a healthy addiction. There’s no need to seek treatment next time you feel that familiar rush of romantic feelings — just relax and enjoy the chemical reaction!