One indication that someone could be toxic is their lack of interest in others. Some toxic people talk about themselves constantly and show very little regard for other people, turning the conversation back to themselves whenever possible. This kind of behavior makes it harder to build friendships as it can have an effect on how valued the person makes others feel.

Far from examining their own behavior, toxic people tend to enjoy judging others’ behavior and commenting on it. They’ll often judge others for their appearance, job, financial situation, relationships, family and more. Being around someone who is so judgmental can cause both confidence and self-esteem to take a dip, and being judgmental yourself can indicate unhappiness.

Unless they specifically ask for it, giving someone advice can be patronizing and interfering. Toxic people are especially prone to do so when it’s inappropriate or even when the other person has made clear it’s unwelcome. According to one study found in the National Library of Medicine, it may offer them a feeling of superiority and control.

When someone is unhappy, unkind or feeling anxious, they may develop a habit of focusing on others rather than doing their own introspection. They take information, or even make up lies, about other people and spread gossip in an effort to hurt the other person’s reputation and perhaps even hurt their credibility should they speak out about the toxic person’s behavior.

Constant negativity could be quite toxic to both the person doing it and the people around them. Not only are negative and pessimistic thoughts detrimental to one’s own confidence and self-esteem, but they could be draining to others who have to be subjected to the constant negativity. This kind of attitude can even affect a person physically in the form of cardiac issues.

Habitual criticism is one of the ways people don’t realize they’re offending their children and serves to put people down. This can have an effect on the recipient’s self-esteem and cause anger and tension, as well as difficulties in handling future disagreements.

Toxic people may insult others, as well as subtly do so in the form of jokes and backhanded compliments, because they themselves could be unhappy or emotionally unstable. This causes others to feel hurt and self-doubt that can be quite lasting, but there are some easy ways to be more polite.

Gossip is an etiquette rule many people don’t know they are breaking, and just one way that toxic people engage in relational aggression, a type of aggression in which one causes harm to another by damaging their relationships or social status. Toxic people often exclude people or encourage social ostracism, which can be very damaging to a person, often having psychological effects.

While a toxic person may feed off others for support and help in their own times of need, they could be reluctant to return the favor. A toxic friend can be great to have when times are good, but don’t expect them to be around to lend a hand or a shoulder when you’re going through some rougher days and need a bit of support to help combat the stress.

Unless you’re putting down boundaries with someone with whom you know communication is futile, giving another person the silent treatment is a toxic behavior. Not only does this make the other person feel rejected and undesirable, but it also helps the toxic person avoid any confrontation about their own behavior.

While sometimes it is necessary to tell a white lie like the tooth fairy to kids, frequent and intentional lying is a sign that a person is toxic and difficult to deal with. Whether it’s telling constant small fibs or huge lies that affect your relationship, this kind of behavior can undermine any trust in their relationships, and more honesty has actually been proven to improve your mental and physical health.

A specific kind of lying, gaslighting is when a person tries to create doubt about another person or group’s reality. When being gaslighted, you’ll find that you question your own memory or perception of events and sometimes even your own sanity.

Instead of being straightforward and trying to communicate their needs, toxic people tend to try to control others outright through covert means. A toxic person does not care about what others want or need but may choose to manipulate a situation to attain a goal that will benefit them, a habit that fosters mistrust.

It’s important to show gratitude every day, and one study published in Social Psychology and Personality Science found that gratitude lowers aggression in addition to improving mental well-being.

A study conducted by the Harvard Business School found that overconfident workers are more likely to be toxic in the workplace. The study found that those who overestimate their own abilities are also more likely to engage in misconduct, as they tend to believe in a higher likelihood of a good outcome as opposed to those who don’t overestimate their abilities.

A toxic person may become unhappy when they perceive that someone else is having some sort of success or happiness. Instead of being a good friend and noticing and appreciating the other person’s hard work, the toxic person may feel resentful and get aggressive. This could show by minimizing other people’s accomplishments or insulting them.

If you’re ever trying to vent about something that upsets you and the other person makes you feel as if you’re overreacting, that’s a toxic behavior. It’s understandable to seek validation, and your emotions are valid. Having your feelings invalidated can actually affect your emotional reactivity and regulation negatively.

It’s important to put down boundaries with others in order to protect your own mental and emotional health. However, a person who is toxic will attempt to cross those boundaries. Entitlement to other people’s time and space is not only damaging to relationships and other people’s sense of safety, but it also could be violating.

Getting physical is never OK, and it is unfortunately a common warning sign in many toxic relationships. Domestic violence is a pattern of behavior that one partner may use to maintain power and control over another, but space and comfort could also be invaded in the workplace, school or among friends.

Toxic people rarely apologize, if at all. As they are loath to take responsibility for their actions, they are unlikely to say they’re sorry, since doing so would mean having to face consequences or make the effort to do better. However, apologizing is an important part of maintaining relationships and even the key to a lasting marriage.

Another way toxic people attempt to get what they want is through guilting others, which is not a good way to create a healthy home or environment. If you refuse to go along with a toxic person’s wishes, be prepared for them to try to make you feel like a bad person for it in order to get you to give in.

Yelling or shouting at someone can be a form of psychological abuse, as it’s done to bring damage to a person’s self-esteem. Such behavior can cause quite a bit of stress for someone else, which itself causes all sorts of scary symptoms.

If someone is feeling insecure, they may overcompensate by trying to bolster their own image by bragging about their talents and accomplishments. While it's nice to acknowledge your lifetime achievements, toxic people will often do this in a way that’s meant to show how much better they are than others, and they’ll often put down those around them in the process, as well as annoy them.

One particularly difficult toxic behavior to deal with is when the other person is simply inconsistent in their treatment of you. They will change their outlook and their opinions on people, events and other subject matter to whatever suits them, and often this results in switching between a hot and cold attitude toward friends and family. Children who experienced this kind of behavior from their parents, in particular, struggle with self-esteem and their own relationships as they get older.

Many toxic people will do anything to avoid accepting responsibility for mistakes or toxic behaviors. They tend to shift blame to others or on their circumstances; nothing is ever their fault. This can be especially damaging when the toxic person is treating others badly, as they will make their victims feel as though they have done something to deserve the abuse, a toxic habit that can seriously damage relationships.

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