To find out if you have Mars and the Sun conjunct check in the Birth Chart calculator if you see Su and Ma together in the same square or triangle(zodiac sign). To find out if you have an aspect between these two planets check the aspect table on the side of the birth chart. Anything above 30 points in aspect will be felt strongly. This is a very fiery combination! The two most masculine planets coming together by conjunction of a strong aspect will make the person more proactive and action oriented. A woman with this position will have more masculine qualities like initiative, courage and go getting attitude. Sitting without anything to do, any task to work on or any project to focus on, can be the worst punishment for such a person. It can actually lead to frustration, dejection and eventually psychological and health issues! If you have such a child or you yourself are this person, you need to keep yourself busy, or else the impulsive energy of this combination will drive you up the walls with dissatisfaction and even self-resentment which will lead you to risky, silly, excessive or downright dangerous behaviors.
The energy should be harnessed for something productive or at least physical exercise while no other project is present, this way you will save yourself a lot of headache caused by reckless actions or frustrated pent up energy. Bisque, martial and invigorating exercises with lots of movement and change(not endurance, repetitive ones) like kick boxing, aerobics, interval training are perfect for the Sun Mars person. Competitive sports are also great for the Sun Mars aspect person, because they get them very excited and feeling alive! But a word of warning, if you have the Sun Mars conjunction, it is best that you do not do competitive or pair sports like tennis, squash, etc because then Mars becomes agitated by the conjunction and proximity of the Sun and he gets angry! Any planet in conjunction close to the Sun, get agitated and reacts in less healthy way. With Mars, this means the person being a bad sport, overly competitive and irritated by the possibility of not winning. A lot of Mars conjunct Sun people, are so painfully competitive that they refuse to compete or even fight with anyone as they feel frustrated about the whole thing even before it starts!
So you will find many Mars Sun conjunct people, shy away from challenges, competition and situations of confrontation on the whole, because they subconsciously do not want all the agro and negative feelings which come with this! For them it is best to do sports which have them competing with themselves and also more relaxing such, which do not overly inflame their hot nature: swimming is one good such. Also drinking more water is recommended to counteract their fiery nature and keep them hydrated, because the Sun, Mars conjunction tends to inflammations, fevers, sudden and other conditions caused by heat and dryness. The conjunction of the Sun to Mars can weaken the organs and functions ruled by Mars like the nervous system, the sight, red blood cells, adrenals, male hormones, etc so they should check these more often for health issues. While the aspect between Sun and Mars will not harm these these.
Sun Mars aspect people(not the conjunction) are fantastic at confrontation and competition. They are a good sport, take the winning and loosing with more detachment, but give it their all! So if you need someone to fight a cause for you, to defend you in court, to always take the right actions when the going gets tough and especially in crisis and intense situations, a trouble shooter, a problem solver, a fixer, then find your self Sun Aspect Mars person. The sun conjunction Mars people can also do all these things, just as good, but they feel agitated in the process, they can throw tantrums, explode more easily and sometimes do overly rash things. Their energy is more tense and uncomfortable for themselves and others around them, when in situations of crisis or challenges. They will be more feisty, pushy, hurtful to others when confronted directly or when going after a goal than the someone with the aspect. Even if they do not show outwardly these more rough Mars qualities, they will feel powerful inner frustration when problems need to be fixed immediately or a fight fought but will do it quite well anyway after agitating themselves and others around first!
Why is this so with the conjunction? Because the Sun usually represents a powerful authority figure like the father, who was disrespecting the will of the person while growing up and later in life the person feels very defensive when someone challenges their will and other Martial qualities. So they will react more sensitively to anyone telling them what to do or trying to boss them around. They had such a person in their life as young and were often forced sometimes by physical intimidation even, to do and follow orders which were usually not to their liking. There is always a rebellious and unruly streak in the Sun/Mars conjunction people, who do much better in environments where they are their own bosses than in ones where someone is there to tell what to do all the time. Or if they have a boss, there can be more frictions with this person, who will often exhibit pushy, bullying or more reactive behavior towards the person. And the person will so show these behaviors to others in their life. In most cases the person is good willing, just they have a more abrasive way of imposing their will on others and going after the things they think are right. Age tends to mellow these behaviors. The aspect Sun Mars people, cam also exhibit sometimes these same attitudes, but as we said they are less touchy about the use of power, more consistent in following they goals and more objective and productive in situations of competition, challenge, crises or even danger. Both the Aspect and the conjunction are amazing at going after and making their goals happen, with the only difference that the conjunction people get more agitated in the process than the aspect people.