When you're both positive

Some people with HIV prefer to have relationships with other HIV positive people. It can seem simpler and feel more comfortable when a partner knows what that’s like.

These are sometimes called seroconcordant relationships (as opposed to serodiscordant relationships, where only one of the partners has HIV).

However, there's no reason to be put off having a relationship with someone who is HIV negative. If you're on treatment and have an undetectable viral load you cannot pass your HIV on to them, even if no condoms are used.

Reinfection is when:

• you’re HIV positive
• you have unprotected sex with another person with HIV
• one or both of you has a detectable viral load
• you pick up (or pass on) a different strain of the virus.

This can be a problem if one person’s strain is resistant to particular antiretrovirals.

Reinfection used to be more of an issue when we understood less about the link between viral load and infectiousness. We now know that if you’re taking HIV medication and have an undetectable viral load you can’t pass on HIV.

In the UK, national guidelines currently recommend that anyone with HIV who is ready to commit to treatment should start it regardless of their CD4 count (a measure of your immune system's health).

This means more people will be on treatment sooner and will have an undetectable viral load, so although reinfection is a theoretical risk, it’s unlikely.

If you had drug-resistant HIV, your viral load would be more likely to be detectable. You would be aware of that, meaning you could use protection to avoid the risk of reinfection. An undetectable viral load indicates your HIV isn't resistant to your medication.

If you have a detectable viral load or don’t know whether the person you’re having sex with is undetectable, using condoms will prevent reinfection.

Another issue to consider if you have sex without a condom is the chance you’ll pick up a sexually transmitted infection (STI).

Sex without a condom can also result in an unplanned pregnancy if other contraception is not being used.

You and your partner should talk to each other and agree whether your relationship will be monogamous (no sex outside the relationship) or open (sex with others allowed).

There are risks in not discussing it and assuming that your partner agrees with you. Some people who think they’re in a monogamous relationship find out that their partner has had sex with others.

Both monogamous and open relationships can bring benefits and challenges. For example, some couples in monogamous relationships say they enjoy feeling both physically and emotionally committed to only one person. However, they may feel frustrated if they have a higher or lower sex drive than their partner.

Some couples in open relationships say they enjoy the sense of freedom and variety it can bring, but it can also highlight any feelings of jealousy or insecurity within the relationship. Mutual trust and honest communication are vital in both monogamous and open relationships.

If you both agree to be monogamous it’s important to discuss what would happen if either of you broke this agreement. If either of you feel that you must hide the fact that you’ve had sex outside the relationship, that can seriously threaten your relationship.

One advantage of monogamy is that no STIs are likely to come into your relationship.

Using condoms with people outside your relationship will make it less likely that you’ll pick up infections (and give them to your partner) although some STIs can be passed on despite using condoms and through oral sex.